Deprecate Spec.concretize/Spec.concretized in favor of spack.concretize.concretize_one (#47971)

The methods spack.spec.Spec.concretize and spack.spec.Spec.concretized
are deprecated in favor of spack.concretize.concretize_one.

This will resolve a circular dependency between the spack.spec and
spack.concretize in the next Spack release.

lib/spack/docs/developer_guide.rst

@@ -543,10 +543,10 @@ With either interpreter you can run a single command:
 
 .. code-block:: console
 
-   $ spack python -c 'from spack.spec import Spec; Spec("python").concretized()'
+   $ spack python -c 'from spack.concretize import concretize_one; concretize_one("python")'
    ...
 
-   $ spack python -i ipython -c 'from spack.spec import Spec; Spec("python").concretized()'
+   $ spack python -i ipython -c 'from spack.concretize import concretize_one; concretize_one("python")'
    Out[1]: ...
 
 or a file:

lib/spack/spack/bootstrap/core.py

@@ -34,6 +34,7 @@
 from llnl.util.lang import GroupedExceptionHandler
 
 import spack.binary_distribution
+import spack.concretize
 import spack.config
 import spack.detection
 import spack.mirrors.mirror
@@ -270,10 +271,10 @@ def try_import(self, module: str, abstract_spec_str: str) -> bool:
                 bootstrapper = ClingoBootstrapConcretizer(configuration=spack.config.CONFIG)
                 concrete_spec = bootstrapper.concretize()
             else:
-                concrete_spec = spack.spec.Spec(
+                abstract_spec = spack.spec.Spec(
                     abstract_spec_str + " ^" + spec_for_current_python()
                 )
-                concrete_spec.concretize()
+                concrete_spec = spack.concretize.concretize_one(abstract_spec)
 
         msg = "[BOOTSTRAP MODULE {0}] Try installing '{1}' from sources"
         tty.debug(msg.format(module, abstract_spec_str))
@@ -299,7 +300,7 @@ def try_search_path(self, executables: Tuple[str], abstract_spec_str: str) -> bo
         # might reduce compilation time by a fair amount
         _add_externals_if_missing()
 
-        concrete_spec = spack.spec.Spec(abstract_spec_str).concretized()
+        concrete_spec = spack.concretize.concretize_one(abstract_spec_str)
         msg = "[BOOTSTRAP] Try installing '{0}' from sources"
         tty.debug(msg.format(abstract_spec_str))
         with spack.config.override(self.mirror_scope):

lib/spack/spack/cmd/__init__.py

@@ -202,7 +202,7 @@ def _concretize_spec_pairs(
     # Special case for concretizing a single spec
     if len(to_concretize) == 1:
         abstract, concrete = to_concretize[0]
-        return [concrete or abstract.concretized(tests=tests)]
+        return [concrete or spack.concretize.concretize_one(abstract, tests=tests)]
 
     # Special case if every spec is either concrete or has an abstract hash
     if all(
@@ -254,9 +254,9 @@ def matching_spec_from_env(spec):
     """
     env = ev.active_environment()
     if env:
-        return env.matching_spec(spec) or spec.concretized()
+        return env.matching_spec(spec) or spack.concretize.concretize_one(spec)
     else:
-        return spec.concretized()
+        return spack.concretize.concretize_one(spec)
 
 
 def matching_specs_from_env(specs):

lib/spack/spack/cmd/bootstrap.py

@@ -14,9 +14,9 @@
 import spack.bootstrap
 import spack.bootstrap.config
 import spack.bootstrap.core
+import spack.concretize
 import spack.config
 import spack.mirrors.utils
-import spack.spec
 import spack.stage
 import spack.util.path
 import spack.util.spack_yaml
@@ -397,7 +397,7 @@ def _mirror(args):
         llnl.util.tty.msg(msg.format(spec_str, mirror_dir))
         # Suppress tty from the call below for terser messages
         llnl.util.tty.set_msg_enabled(False)
-        spec = spack.spec.Spec(spec_str).concretized()
+        spec = spack.concretize.concretize_one(spec_str)
         for node in spec.traverse():
             spack.mirrors.utils.create(mirror_dir, [node])
         llnl.util.tty.set_msg_enabled(True)

lib/spack/spack/cmd/buildcache.py

@@ -16,6 +16,7 @@
 
 import spack.binary_distribution as bindist
 import spack.cmd
+import spack.concretize
 import spack.config
 import spack.deptypes as dt
 import spack.environment as ev
@@ -554,8 +555,7 @@ def check_fn(args: argparse.Namespace):
         tty.msg("No specs provided, exiting.")
         return
 
-    for spec in specs:
+    specs = [spack.concretize.concretize_one(s) for s in specs]
-        spec.concretize()
 
     # Next see if there are any configured binary mirrors
     configured_mirrors = spack.config.get("mirrors", scope=args.scope)
@@ -623,7 +623,7 @@ def save_specfile_fn(args):
     root = specs[0]
 
     if not root.concrete:
-        root.concretize()
+        root = spack.concretize.concretize_one(root)
 
     save_dependency_specfiles(
         root, args.specfile_dir, dependencies=spack.cmd.parse_specs(args.specs)

lib/spack/spack/cmd/deprecate.py

@@ -18,6 +18,7 @@
 from llnl.util.symlink import symlink
 
 import spack.cmd
+import spack.concretize
 import spack.environment as ev
 import spack.installer
 import spack.store
@@ -103,7 +104,7 @@ def deprecate(parser, args):
     )
 
     if args.install:
-        deprecator = specs[1].concretized()
+        deprecator = spack.concretize.concretize_one(specs[1])
     else:
         deprecator = spack.cmd.disambiguate_spec(specs[1], env, local=True)
 

lib/spack/spack/cmd/dev_build.py

@@ -10,6 +10,7 @@
 import spack.build_environment
 import spack.cmd
 import spack.cmd.common.arguments
+import spack.concretize
 import spack.config
 import spack.repo
 from spack.cmd.common import arguments
@@ -114,7 +115,7 @@ def dev_build(self, args):
 
     # Forces the build to run out of the source directory.
     spec.constrain("dev_path=%s" % source_path)
-    spec.concretize()
+    spec = spack.concretize.concretize_one(spec)
 
     if spec.installed:
         tty.error("Already installed in %s" % spec.prefix)

lib/spack/spack/cmd/install.py

@@ -13,6 +13,7 @@
 from llnl.util import lang, tty
 
 import spack.cmd
+import spack.concretize
 import spack.config
 import spack.environment as ev
 import spack.paths
@@ -450,7 +451,7 @@ def concrete_specs_from_file(args):
             else:
                 s = spack.spec.Spec.from_json(f)
 
-        concretized = s.concretized()
+        concretized = spack.concretize.concretize_one(s)
         if concretized.dag_hash() != s.dag_hash():
             msg = 'skipped invalid file "{0}". '
             msg += "The file does not contain a concrete spec."

lib/spack/spack/cmd/make_installer.py

@@ -7,9 +7,9 @@
 
 from llnl.path import convert_to_posix_path
 
+import spack.concretize
 import spack.paths
 import spack.util.executable
-from spack.spec import Spec
 
 description = "generate Windows installer"
 section = "admin"
@@ -65,8 +65,7 @@ def make_installer(parser, args):
     """
     if sys.platform == "win32":
         output_dir = args.output_dir
-        cmake_spec = Spec("cmake")
+        cmake_spec = spack.concretize.concretize_one("cmake")
-        cmake_spec.concretize()
         cmake_path = os.path.join(cmake_spec.prefix, "bin", "cmake.exe")
         cpack_path = os.path.join(cmake_spec.prefix, "bin", "cpack.exe")
         spack_source = args.spack_source

lib/spack/spack/cmd/mirror.py

@@ -492,7 +492,7 @@ def extend_with_additional_versions(specs, num_versions):
         mirror_specs = spack.mirrors.utils.get_all_versions(specs)
     else:
         mirror_specs = spack.mirrors.utils.get_matching_versions(specs, num_versions=num_versions)
-    mirror_specs = [x.concretized() for x in mirror_specs]
+    mirror_specs = [spack.concretize.concretize_one(x) for x in mirror_specs]
     return mirror_specs
 
 

lib/spack/spack/concretize.py

@@ -37,13 +37,12 @@ def enable_compiler_existence_check():
 
 SpecPairInput = Tuple[Spec, Optional[Spec]]
 SpecPair = Tuple[Spec, Spec]
-SpecLike = Union[Spec, str]
 TestsType = Union[bool, Iterable[str]]
 
 
-def concretize_specs_together(
+def _concretize_specs_together(
-    abstract_specs: Sequence[SpecLike], tests: TestsType = False
+    abstract_specs: Sequence[Spec], tests: TestsType = False
-) -> Sequence[Spec]:
+) -> List[Spec]:
     """Given a number of specs as input, tries to concretize them together.
 
     Args:
@@ -51,11 +50,10 @@ def concretize_specs_together(
         tests: list of package names for which to consider tests dependencies. If True, all nodes
             will have test dependencies. If False, test dependencies will be disregarded.
     """
-    import spack.solver.asp
+    from spack.solver.asp import Solver
 
     allow_deprecated = spack.config.get("config:deprecated", False)
-    solver = spack.solver.asp.Solver()
+    result = Solver().solve(abstract_specs, tests=tests, allow_deprecated=allow_deprecated)
-    result = solver.solve(abstract_specs, tests=tests, allow_deprecated=allow_deprecated)
     return [s.copy() for s in result.specs]
 
 
@@ -72,7 +70,7 @@ def concretize_together(
     """
     to_concretize = [concrete if concrete else abstract for abstract, concrete in spec_list]
     abstract_specs = [abstract for abstract, _ in spec_list]
-    concrete_specs = concretize_specs_together(to_concretize, tests=tests)
+    concrete_specs = _concretize_specs_together(to_concretize, tests=tests)
     return list(zip(abstract_specs, concrete_specs))
 
 
@@ -90,7 +88,7 @@ def concretize_together_when_possible(
         tests: list of package names for which to consider tests dependencies. If True, all nodes
             will have test dependencies. If False, test dependencies will be disregarded.
     """
-    import spack.solver.asp
+    from spack.solver.asp import Solver
 
     to_concretize = [concrete if concrete else abstract for abstract, concrete in spec_list]
     old_concrete_to_abstract = {
@@ -98,9 +96,8 @@ def concretize_together_when_possible(
     }
 
     result_by_user_spec = {}
-    solver = spack.solver.asp.Solver()
     allow_deprecated = spack.config.get("config:deprecated", False)
-    for result in solver.solve_in_rounds(
+    for result in Solver().solve_in_rounds(
         to_concretize, tests=tests, allow_deprecated=allow_deprecated
     ):
         result_by_user_spec.update(result.specs_by_input)
@@ -124,7 +121,7 @@ def concretize_separately(
         tests: list of package names for which to consider tests dependencies. If True, all nodes
             will have test dependencies. If False, test dependencies will be disregarded.
     """
-    import spack.bootstrap
+    from spack.bootstrap import ensure_bootstrap_configuration, ensure_clingo_importable_or_raise
 
     to_concretize = [abstract for abstract, concrete in spec_list if not concrete]
     args = [
@@ -134,8 +131,8 @@ def concretize_separately(
     ]
     ret = [(i, abstract) for i, abstract in enumerate(to_concretize) if abstract.concrete]
     # Ensure we don't try to bootstrap clingo in parallel
-    with spack.bootstrap.ensure_bootstrap_configuration():
+    with ensure_bootstrap_configuration():
-        spack.bootstrap.ensure_clingo_importable_or_raise()
+        ensure_clingo_importable_or_raise()
 
     # Ensure all the indexes have been built or updated, since
     # otherwise the processes in the pool may timeout on waiting
@@ -190,10 +187,52 @@ def _concretize_task(packed_arguments: Tuple[int, str, TestsType]) -> Tuple[int,
     index, spec_str, tests = packed_arguments
     with tty.SuppressOutput(msg_enabled=False):
         start = time.time()
-        spec = Spec(spec_str).concretized(tests=tests)
+        spec = concretize_one(Spec(spec_str), tests=tests)
         return index, spec, time.time() - start
 
 
+def concretize_one(spec: Union[str, Spec], tests: TestsType = False) -> Spec:
+    """Return a concretized copy of the given spec.
+
+    Args:
+        tests: if False disregard 'test' dependencies, if a list of names activate them for
+            the packages in the list, if True activate 'test' dependencies for all packages.
+    """
+    from spack.solver.asp import Solver, SpecBuilder
+
+    if isinstance(spec, str):
+        spec = Spec(spec)
+    spec = spec.lookup_hash()
+
+    if spec.concrete:
+        return spec.copy()
+
+    for node in spec.traverse():
+        if not node.name:
+            raise spack.error.SpecError(
+                f"Spec {node} has no name; cannot concretize an anonymous spec"
+            )
+
+    allow_deprecated = spack.config.get("config:deprecated", False)
+    result = Solver().solve([spec], tests=tests, allow_deprecated=allow_deprecated)
+
+    # take the best answer
+    opt, i, answer = min(result.answers)
+    name = spec.name
+    # TODO: Consolidate this code with similar code in solve.py
+    if spec.virtual:
+        providers = [s.name for s in answer.values() if s.package.provides(name)]
+        name = providers[0]
+
+    node = SpecBuilder.make_node(pkg=name)
+    assert (
+        node in answer
+    ), f"cannot find {name} in the list of specs {','.join([n.pkg for n in answer.keys()])}"
+
+    concretized = answer[node]
+    return concretized
+
+
 class UnavailableCompilerVersionError(spack.error.SpackError):
     """Raised when there is no available compiler that satisfies a
     compiler spec."""

lib/spack/spack/solver/asp.py

@@ -67,7 +67,7 @@
 
 GitOrStandardVersion = Union[spack.version.GitVersion, spack.version.StandardVersion]
 
-TransformFunction = Callable[["spack.spec.Spec", List[AspFunction]], List[AspFunction]]
+TransformFunction = Callable[[spack.spec.Spec, List[AspFunction]], List[AspFunction]]
 
 #: Enable the addition of a runtime node
 WITH_RUNTIME = sys.platform != "win32"
@@ -127,8 +127,8 @@ def __str__(self):
 
 @contextmanager
 def named_spec(
-    spec: Optional["spack.spec.Spec"], name: Optional[str]
+    spec: Optional[spack.spec.Spec], name: Optional[str]
-) -> Iterator[Optional["spack.spec.Spec"]]:
+) -> Iterator[Optional[spack.spec.Spec]]:
     """Context manager to temporarily set the name of a spec"""
     if spec is None or name is None:
         yield spec
@@ -747,11 +747,11 @@ def on_model(model):
 class KnownCompiler(NamedTuple):
     """Data class to collect information on compilers"""
 
-    spec: "spack.spec.Spec"
+    spec: spack.spec.Spec
     os: str
     target: str
     available: bool
-    compiler_obj: Optional["spack.compiler.Compiler"]
+    compiler_obj: Optional[spack.compiler.Compiler]
 
     def _key(self):
         return self.spec, self.os, self.target
@@ -1386,7 +1386,7 @@ def effect_rules(self):
 
     def define_variant(
         self,
-        pkg: "Type[spack.package_base.PackageBase]",
+        pkg: Type[spack.package_base.PackageBase],
         name: str,
         when: spack.spec.Spec,
         variant_def: vt.Variant,
@@ -1490,7 +1490,7 @@ def define_auto_variant(self, name: str, multi: bool):
             )
         )
 
-    def variant_rules(self, pkg: "Type[spack.package_base.PackageBase]"):
+    def variant_rules(self, pkg: Type[spack.package_base.PackageBase]):
         for name in pkg.variant_names():
             self.gen.h3(f"Variant {name} in package {pkg.name}")
             for when, variant_def in pkg.variant_definitions(name):
@@ -1681,8 +1681,8 @@ def dependency_holds(input_spec, requirements):
     def _gen_match_variant_splice_constraints(
         self,
         pkg,
-        cond_spec: "spack.spec.Spec",
+        cond_spec: spack.spec.Spec,
-        splice_spec: "spack.spec.Spec",
+        splice_spec: spack.spec.Spec,
         hash_asp_var: "AspVar",
         splice_node,
         match_variants: List[str],
@@ -2977,7 +2977,7 @@ def _specs_from_requires(self, pkg_name, section):
             for s in spec_group[key]:
                 yield _spec_with_default_name(s, pkg_name)
 
-    def pkg_class(self, pkg_name: str) -> typing.Type["spack.package_base.PackageBase"]:
+    def pkg_class(self, pkg_name: str) -> typing.Type[spack.package_base.PackageBase]:
         request = pkg_name
         if pkg_name in self.explicitly_required_namespaces:
             namespace = self.explicitly_required_namespaces[pkg_name]
@@ -3096,7 +3096,7 @@ def __init__(self, configuration) -> None:
 
             self.compilers.add(candidate)
 
-    def with_input_specs(self, input_specs: List["spack.spec.Spec"]) -> "CompilerParser":
+    def with_input_specs(self, input_specs: List[spack.spec.Spec]) -> "CompilerParser":
         """Accounts for input specs when building the list of possible compilers.
 
         Args:
@@ -3136,7 +3136,7 @@ def with_input_specs(self, input_specs: List["spack.spec.Spec"]) -> "CompilerPar
 
         return self
 
-    def add_compiler_from_concrete_spec(self, spec: "spack.spec.Spec") -> None:
+    def add_compiler_from_concrete_spec(self, spec: spack.spec.Spec) -> None:
         """Account for compilers that are coming from concrete specs, through reuse.
 
         Args:

lib/spack/spack/spec.py

@@ -86,7 +86,6 @@
 import spack
 import spack.compiler
 import spack.compilers
-import spack.config
 import spack.deptypes as dt
 import spack.error
 import spack.hash_types as ht
@@ -94,7 +93,6 @@
 import spack.platforms
 import spack.provider_index
 import spack.repo
-import spack.solver
 import spack.spec_parser
 import spack.store
 import spack.traverse
@@ -2949,44 +2947,16 @@ def ensure_no_deprecated(root):
             raise SpecDeprecatedError(msg)
 
     def concretize(self, tests: Union[bool, Iterable[str]] = False) -> None:
-        """Concretize the current spec.
+        from spack.concretize import concretize_one
 
-        Args:
+        warnings.warn(
-            tests: if False disregard 'test' dependencies, if a list of names activate them for
+            "`Spec.concretize` is deprecated and will be removed in version 1.0.0. Use "
-                the packages in the list, if True activate 'test' dependencies for all packages.
+            "`spack.concretize.concretize_one` instead.",
-        """
+            category=spack.error.SpackAPIWarning,
-        import spack.solver.asp
+            stacklevel=2,
+        )
 
-        self.replace_hash()
+        self._dup(concretize_one(self, tests))
-
-        for node in self.traverse():
-            if not node.name:
-                raise spack.error.SpecError(
-                    f"Spec {node} has no name; cannot concretize an anonymous spec"
-                )
-
-        if self._concrete:
-            return
-
-        allow_deprecated = spack.config.get("config:deprecated", False)
-        solver = spack.solver.asp.Solver()
-        result = solver.solve([self], tests=tests, allow_deprecated=allow_deprecated)
-
-        # take the best answer
-        opt, i, answer = min(result.answers)
-        name = self.name
-        # TODO: Consolidate this code with similar code in solve.py
-        if self.virtual:
-            providers = [spec.name for spec in answer.values() if spec.package.provides(name)]
-            name = providers[0]
-
-        node = spack.solver.asp.SpecBuilder.make_node(pkg=name)
-        assert (
-            node in answer
-        ), f"cannot find {name} in the list of specs {','.join([n.pkg for n in answer.keys()])}"
-
-        concretized = answer[node]
-        self._dup(concretized)
 
     def _mark_root_concrete(self, value=True):
         """Mark just this spec (not dependencies) concrete."""
@@ -3076,19 +3046,16 @@ def _finalize_concretization(self):
             spec._cached_hash(ht.dag_hash)
 
     def concretized(self, tests: Union[bool, Iterable[str]] = False) -> "Spec":
-        """This is a non-destructive version of concretize().
+        from spack.concretize import concretize_one
 
-        First clones, then returns a concrete version of this package
+        warnings.warn(
-        without modifying this package.
+            "`Spec.concretized` is deprecated and will be removed in version 1.0.0. Use "
+            "`spack.concretize.concretize_one` instead.",
+            category=spack.error.SpackAPIWarning,
+            stacklevel=2,
+        )
 
-        Args:
+        return concretize_one(self, tests)
-            tests (bool or list): if False disregard 'test' dependencies,
-                if a list of names activate them for the packages in the list,
-                if True activate 'test' dependencies for all packages.
-        """
-        clone = self.copy()
-        clone.concretize(tests=tests)
-        return clone
 
     def index(self, deptype="all"):
         """Return a dictionary that points to all the dependencies in this

lib/spack/spack/test/abi_splicing.py

@@ -7,6 +7,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.config
 import spack.deptypes as dt
 import spack.solver.asp
@@ -21,7 +22,7 @@ def __init__(self, specs: List[str]) -> None:
         self.concr_specs = []
 
     def __enter__(self):
-        self.concr_specs = [Spec(s).concretized() for s in self.req_specs]
+        self.concr_specs = [spack.concretize.concretize_one(s) for s in self.req_specs]
         for s in self.concr_specs:
             PackageInstaller([s.package], fake=True, explicit=True).install()
 
@@ -62,13 +63,13 @@ def _has_build_dependency(spec: Spec, name: str):
 def test_simple_reuse(splicing_setup):
     with CacheManager(["splice-z@1.0.0+compat"]):
         spack.config.set("packages", _make_specs_non_buildable(["splice-z"]))
-        assert Spec("splice-z").concretized().satisfies(Spec("splice-z"))
+        assert spack.concretize.concretize_one("splice-z").satisfies(Spec("splice-z"))
 
 
 def test_simple_dep_reuse(splicing_setup):
     with CacheManager(["splice-z@1.0.0+compat"]):
         spack.config.set("packages", _make_specs_non_buildable(["splice-z"]))
-        assert Spec("splice-h@1").concretized().satisfies(Spec("splice-h@1"))
+        assert spack.concretize.concretize_one("splice-h@1").satisfies(Spec("splice-h@1"))
 
 
 def test_splice_installed_hash(splicing_setup):
@@ -81,9 +82,9 @@ def test_splice_installed_hash(splicing_setup):
         spack.config.set("packages", packages_config)
         goal_spec = Spec("splice-t@1 ^splice-h@1.0.2+compat ^splice-z@1.0.0")
         with pytest.raises(Exception):
-            goal_spec.concretized()
+            spack.concretize.concretize_one(goal_spec)
         _enable_splicing()
-        assert goal_spec.concretized().satisfies(goal_spec)
+        assert spack.concretize.concretize_one(goal_spec).satisfies(goal_spec)
 
 
 def test_splice_build_splice_node(splicing_setup):
@@ -91,9 +92,9 @@ def test_splice_build_splice_node(splicing_setup):
         spack.config.set("packages", _make_specs_non_buildable(["splice-t"]))
         goal_spec = Spec("splice-t@1 ^splice-h@1.0.2+compat ^splice-z@1.0.0+compat")
         with pytest.raises(Exception):
-            goal_spec.concretized()
+            spack.concretize.concretize_one(goal_spec)
         _enable_splicing()
-        assert goal_spec.concretized().satisfies(goal_spec)
+        assert spack.concretize.concretize_one(goal_spec).satisfies(goal_spec)
 
 
 def test_double_splice(splicing_setup):
@@ -107,9 +108,9 @@ def test_double_splice(splicing_setup):
         spack.config.set("packages", freeze_builds_config)
         goal_spec = Spec("splice-t@1 ^splice-h@1.0.2+compat ^splice-z@1.0.2+compat")
         with pytest.raises(Exception):
-            goal_spec.concretized()
+            spack.concretize.concretize_one(goal_spec)
         _enable_splicing()
-        assert goal_spec.concretized().satisfies(goal_spec)
+        assert spack.concretize.concretize_one(goal_spec).satisfies(goal_spec)
 
 
 # The next two tests are mirrors of one another
@@ -126,10 +127,10 @@ def test_virtual_multi_splices_in(splicing_setup):
         spack.config.set("packages", _make_specs_non_buildable(["depends-on-virtual-with-abi"]))
         for gs in goal_specs:
             with pytest.raises(Exception):
-                Spec(gs).concretized()
+                spack.concretize.concretize_one(gs)
         _enable_splicing()
         for gs in goal_specs:
-            assert Spec(gs).concretized().satisfies(gs)
+            assert spack.concretize.concretize_one(gs).satisfies(gs)
 
 
 def test_virtual_multi_can_be_spliced(splicing_setup):
@@ -143,12 +144,12 @@ def test_virtual_multi_can_be_spliced(splicing_setup):
     ]
     with CacheManager(cache):
         spack.config.set("packages", _make_specs_non_buildable(["depends-on-virtual-with-abi"]))
-        with pytest.raises(Exception):
+        for gs in goal_specs:
-            for gs in goal_specs:
+            with pytest.raises(Exception):
-                Spec(gs).concretized()
+                spack.concretize.concretize_one(gs)
         _enable_splicing()
         for gs in goal_specs:
-            assert Spec(gs).concretized().satisfies(gs)
+            assert spack.concretize.concretize_one(gs).satisfies(gs)
 
 
 def test_manyvariant_star_matching_variant_splice(splicing_setup):
@@ -166,10 +167,10 @@ def test_manyvariant_star_matching_variant_splice(splicing_setup):
         spack.config.set("packages", freeze_build_config)
         for goal in goal_specs:
             with pytest.raises(Exception):
-                goal.concretized()
+                spack.concretize.concretize_one(goal)
         _enable_splicing()
         for goal in goal_specs:
-            assert goal.concretized().satisfies(goal)
+            assert spack.concretize.concretize_one(goal).satisfies(goal)
 
 
 def test_manyvariant_limited_matching(splicing_setup):
@@ -188,10 +189,10 @@ def test_manyvariant_limited_matching(splicing_setup):
         spack.config.set("packages", freeze_build_config)
         for s in goal_specs:
             with pytest.raises(Exception):
-                s.concretized()
+                spack.concretize.concretize_one(s)
         _enable_splicing()
         for s in goal_specs:
-            assert s.concretized().satisfies(s)
+            assert spack.concretize.concretize_one(s).satisfies(s)
 
 
 def test_external_splice_same_name(splicing_setup):
@@ -210,7 +211,7 @@ def test_external_splice_same_name(splicing_setup):
         spack.config.set("packages", packages_yaml)
         _enable_splicing()
         for s in goal_specs:
-            assert s.concretized().satisfies(s)
+            assert spack.concretize.concretize_one(s).satisfies(s)
 
 
 def test_spliced_build_deps_only_in_build_spec(splicing_setup):
@@ -219,7 +220,7 @@ def test_spliced_build_deps_only_in_build_spec(splicing_setup):
 
     with CacheManager(cache):
         _enable_splicing()
-        concr_goal = goal_spec.concretized()
+        concr_goal = spack.concretize.concretize_one(goal_spec)
         build_spec = concr_goal._build_spec
         # Spec has been spliced
         assert build_spec is not None
@@ -237,7 +238,7 @@ def test_spliced_transitive_dependency(splicing_setup):
     with CacheManager(cache):
         spack.config.set("packages", _make_specs_non_buildable(["splice-depends-on-t"]))
         _enable_splicing()
-        concr_goal = goal_spec.concretized()
+        concr_goal = spack.concretize.concretize_one(goal_spec)
         # Spec has been spliced
         assert concr_goal._build_spec is not None
         assert concr_goal["splice-t"]._build_spec is not None

lib/spack/spack/test/architecture.py

@@ -133,5 +133,5 @@ def test_concretize_target_ranges(root_target_range, dep_target_range, result, m
         f"pkg-a %gcc@10 foobar=bar target={root_target_range} ^pkg-b target={dep_target_range}"
     )
     with spack.concretize.disable_compiler_existence_check():
-        spec.concretize()
+        spec = spack.concretize.concretize_one(spec)
     assert spec.target == spec["pkg-b"].target == result

lib/spack/spack/test/bindist.py

@@ -28,6 +28,7 @@
 import spack.binary_distribution as bindist
 import spack.caches
 import spack.compilers
+import spack.concretize
 import spack.config
 import spack.fetch_strategy
 import spack.hooks.sbang as sbang
@@ -205,8 +206,9 @@ def test_default_rpaths_create_install_default_layout(temporary_mirror_dir):
     Test the creation and installation of buildcaches with default rpaths
     into the default directory layout scheme.
     """
-    gspec, cspec = Spec("garply").concretized(), Spec("corge").concretized()
+    gspec = spack.concretize.concretize_one("garply")
-    sy_spec = Spec("symly").concretized()
+    cspec = spack.concretize.concretize_one("corge")
+    sy_spec = spack.concretize.concretize_one("symly")
 
     # Install 'corge' without using a cache
     install_cmd("--no-cache", cspec.name)
@@ -253,9 +255,9 @@ def test_default_rpaths_install_nondefault_layout(temporary_mirror_dir):
     Test the creation and installation of buildcaches with default rpaths
     into the non-default directory layout scheme.
     """
-    cspec = Spec("corge").concretized()
+    cspec = spack.concretize.concretize_one("corge")
     # This guy tests for symlink relocation
-    sy_spec = Spec("symly").concretized()
+    sy_spec = spack.concretize.concretize_one("symly")
 
     # Install some packages with dependent packages
     # test install in non-default install path scheme
@@ -276,7 +278,8 @@ def test_relative_rpaths_install_default_layout(temporary_mirror_dir):
     Test the creation and installation of buildcaches with relative
     rpaths into the default directory layout scheme.
     """
-    gspec, cspec = Spec("garply").concretized(), Spec("corge").concretized()
+    gspec = spack.concretize.concretize_one("garply")
+    cspec = spack.concretize.concretize_one("corge")
 
     # Install buildcache created with relativized rpaths
     buildcache_cmd("install", "-uf", cspec.name)
@@ -305,7 +308,7 @@ def test_relative_rpaths_install_nondefault(temporary_mirror_dir):
     Test the installation of buildcaches with relativized rpaths
     into the non-default directory layout scheme.
     """
-    cspec = Spec("corge").concretized()
+    cspec = spack.concretize.concretize_one("corge")
 
     # Test install in non-default install path scheme and relative path
     buildcache_cmd("install", "-uf", cspec.name)
@@ -358,7 +361,8 @@ def test_built_spec_cache(temporary_mirror_dir):
     that cache from a buildcache index."""
     buildcache_cmd("list", "-a", "-l")
 
-    gspec, cspec = Spec("garply").concretized(), Spec("corge").concretized()
+    gspec = spack.concretize.concretize_one("garply")
+    cspec = spack.concretize.concretize_one("corge")
 
     for s in [gspec, cspec]:
         results = bindist.get_mirrors_for_spec(s)
@@ -381,7 +385,7 @@ def test_spec_needs_rebuild(monkeypatch, tmpdir):
     mirror_dir = tmpdir.join("mirror_dir")
     mirror_url = url_util.path_to_file_url(mirror_dir.strpath)
 
-    s = Spec("libdwarf").concretized()
+    s = spack.concretize.concretize_one("libdwarf")
 
     # Install a package
     install_cmd(s.name)
@@ -410,7 +414,7 @@ def test_generate_index_missing(monkeypatch, tmpdir, mutable_config):
     mirror_url = url_util.path_to_file_url(mirror_dir.strpath)
     spack.config.set("mirrors", {"test": mirror_url})
 
-    s = Spec("libdwarf").concretized()
+    s = spack.concretize.concretize_one("libdwarf")
 
     # Install a package
     install_cmd("--no-cache", s.name)
@@ -494,7 +498,7 @@ def mock_list_url(url, recursive=False):
 
 def test_update_sbang(tmp_path, temporary_mirror, mock_fetch, install_mockery):
     """Test relocation of the sbang shebang line in a package script"""
-    s = Spec("old-sbang").concretized()
+    s = spack.concretize.concretize_one("old-sbang")
     PackageInstaller([s.package]).install()
     old_prefix, old_sbang_shebang = s.prefix, sbang.sbang_shebang_line()
     old_contents = f"""\

lib/spack/spack/test/build_distribution.py

@@ -8,15 +8,15 @@
 import pytest
 
 import spack.binary_distribution as bd
+import spack.concretize
 import spack.mirrors.mirror
-import spack.spec
 from spack.installer import PackageInstaller
 
 pytestmark = pytest.mark.not_on_windows("does not run on windows")
 
 
 def test_build_tarball_overwrite(install_mockery, mock_fetch, monkeypatch, tmp_path):
-    spec = spack.spec.Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
     PackageInstaller([spec.package], fake=True).install()
 
     specs = [spec]

lib/spack/spack/test/build_environment.py

@@ -16,6 +16,7 @@
 import spack.build_environment
 import spack.compiler
 import spack.compilers
+import spack.concretize
 import spack.config
 import spack.deptypes as dt
 import spack.package_base
@@ -163,8 +164,7 @@ def test_static_to_shared_library(build_environment):
 @pytest.mark.regression("8345")
 @pytest.mark.usefixtures("config", "mock_packages")
 def test_cc_not_changed_by_modules(monkeypatch, working_env):
-    s = spack.spec.Spec("cmake")
+    s = spack.concretize.concretize_one("cmake")
-    s.concretize()
     pkg = s.package
 
     def _set_wrong_cc(x):
@@ -184,7 +184,7 @@ def test_setup_dependent_package_inherited_modules(
     working_env, mock_packages, install_mockery, mock_fetch
 ):
     # This will raise on regression
-    s = spack.spec.Spec("cmake-client-inheritor").concretized()
+    s = spack.concretize.concretize_one("cmake-client-inheritor")
     PackageInstaller([s.package]).install()
 
 
@@ -277,7 +277,7 @@ def platform_pathsep(pathlist):
         return convert_to_platform_path(pathlist)
 
     # Monkeypatch a pkg.compiler.environment with the required modifications
-    pkg = spack.spec.Spec("cmake").concretized().package
+    pkg = spack.concretize.concretize_one("cmake").package
     monkeypatch.setattr(pkg.compiler, "environment", modifications)
     # Trigger the modifications
     spack.build_environment.setup_package(pkg, False)
@@ -301,7 +301,7 @@ def custom_env(pkg, env):
         env.prepend_path("PATH", test_path)
         env.append_flags("ENV_CUSTOM_CC_FLAGS", "--custom-env-flag1")
 
-    pkg = spack.spec.Spec("cmake").concretized().package
+    pkg = spack.concretize.concretize_one("cmake").package
     monkeypatch.setattr(pkg.compiler, "setup_custom_environment", custom_env)
     spack.build_environment.setup_package(pkg, False)
 
@@ -322,7 +322,7 @@ def test_external_config_env(mock_packages, mutable_config, working_env):
     }
     spack.config.set("packages:cmake", cmake_config)
 
-    cmake_client = spack.spec.Spec("cmake-client").concretized()
+    cmake_client = spack.concretize.concretize_one("cmake-client")
     spack.build_environment.setup_package(cmake_client.package, False)
 
     assert os.environ["TEST_ENV_VAR_SET"] == "yes it's set"
@@ -330,8 +330,7 @@ def test_external_config_env(mock_packages, mutable_config, working_env):
 
 @pytest.mark.regression("9107")
 def test_spack_paths_before_module_paths(config, mock_packages, monkeypatch, working_env):
-    s = spack.spec.Spec("cmake")
+    s = spack.concretize.concretize_one("cmake")
-    s.concretize()
     pkg = s.package
 
     module_path = os.path.join("path", "to", "module")
@@ -352,8 +351,7 @@ def _set_wrong_cc(x):
 
 
 def test_package_inheritance_module_setup(config, mock_packages, working_env):
-    s = spack.spec.Spec("multimodule-inheritance")
+    s = spack.concretize.concretize_one("multimodule-inheritance")
-    s.concretize()
     pkg = s.package
 
     spack.build_environment.setup_package(pkg, False)
@@ -387,8 +385,7 @@ def test_wrapper_variables(
         not in cuda_include_dirs
     )
 
-    root = spack.spec.Spec("dt-diamond")
+    root = spack.concretize.concretize_one("dt-diamond")
-    root.concretize()
 
     for s in root.traverse():
         s.prefix = "/{0}-prefix/".format(s.name)
@@ -453,7 +450,7 @@ def test_external_prefixes_last(mutable_config, mock_packages, working_env, monk
 """
     )
     spack.config.set("packages", cfg_data)
-    top = spack.spec.Spec("dt-diamond").concretized()
+    top = spack.concretize.concretize_one("dt-diamond")
 
     def _trust_me_its_a_dir(path):
         return True
@@ -500,8 +497,7 @@ def test_parallel_false_is_not_propagating(default_mock_concretization):
 )
 def test_setting_dtags_based_on_config(config_setting, expected_flag, config, mock_packages):
     # Pick a random package to be able to set compiler's variables
-    s = spack.spec.Spec("cmake")
+    s = spack.concretize.concretize_one("cmake")
-    s.concretize()
     pkg = s.package
 
     env = EnvironmentModifications()
@@ -533,7 +529,7 @@ def setup_dependent_package(module, dependent_spec):
         assert dependent_module.ninja is not None
         dependent_spec.package.test_attr = True
 
-    externaltool = spack.spec.Spec("externaltest").concretized()
+    externaltool = spack.concretize.concretize_one("externaltest")
     monkeypatch.setattr(
         externaltool["externaltool"].package, "setup_dependent_package", setup_dependent_package
     )
@@ -728,7 +724,7 @@ def test_build_system_globals_only_set_on_root_during_build(default_mock_concret
     But obviously it can lead to very hard to find bugs... We should get rid of those globals and
     define them instead as a property on the package instance.
     """
-    root = spack.spec.Spec("mpileaks").concretized()
+    root = spack.concretize.concretize_one("mpileaks")
     build_variables = ("std_cmake_args", "std_meson_args", "std_pip_args")
 
     # See todo above, we clear out any properties that may have been set by the previous test.

lib/spack/spack/test/build_systems.py

@@ -15,6 +15,7 @@
 import spack.build_systems.autotools
 import spack.build_systems.cmake
 import spack.builder
+import spack.concretize
 import spack.environment
 import spack.error
 import spack.paths
@@ -146,7 +147,7 @@ def test_none_is_allowed(self, default_mock_concretization):
 
     def test_libtool_archive_files_are_deleted_by_default(self, mutable_database):
         # Install a package that creates a mock libtool archive
-        s = Spec("libtool-deletion").concretized()
+        s = spack.concretize.concretize_one("libtool-deletion")
         PackageInstaller([s.package], explicit=True).install()
 
         # Assert the libtool archive is not there and we have
@@ -161,7 +162,7 @@ def test_libtool_archive_files_might_be_installed_on_demand(
     ):
         # Install a package that creates a mock libtool archive,
         # patch its package to preserve the installation
-        s = Spec("libtool-deletion").concretized()
+        s = spack.concretize.concretize_one("libtool-deletion")
         monkeypatch.setattr(
             type(spack.builder.create(s.package)), "install_libtool_archives", True
         )
@@ -175,7 +176,9 @@ def test_autotools_gnuconfig_replacement(self, mutable_database):
         Tests whether only broken config.sub and config.guess are replaced with
         files from working alternatives from the gnuconfig package.
         """
-        s = Spec("autotools-config-replacement +patch_config_files +gnuconfig").concretized()
+        s = spack.concretize.concretize_one(
+            Spec("autotools-config-replacement +patch_config_files +gnuconfig")
+        )
         PackageInstaller([s.package]).install()
 
         with open(os.path.join(s.prefix.broken, "config.sub"), encoding="utf-8") as f:
@@ -194,7 +197,9 @@ def test_autotools_gnuconfig_replacement_disabled(self, mutable_database):
         """
         Tests whether disabling patch_config_files
         """
-        s = Spec("autotools-config-replacement ~patch_config_files +gnuconfig").concretized()
+        s = spack.concretize.concretize_one(
+            Spec("autotools-config-replacement ~patch_config_files +gnuconfig")
+        )
         PackageInstaller([s.package]).install()
 
         with open(os.path.join(s.prefix.broken, "config.sub"), encoding="utf-8") as f:
@@ -219,8 +224,9 @@ def test_autotools_gnuconfig_replacement_no_gnuconfig(self, mutable_database, mo
         enabled, but gnuconfig is not listed as a direct build dependency.
         """
         monkeypatch.setattr(spack.platforms.test.Test, "default", "x86_64")
-        s = Spec("autotools-config-replacement +patch_config_files ~gnuconfig")
+        s = spack.concretize.concretize_one(
-        s.concretize()
+            Spec("autotools-config-replacement +patch_config_files ~gnuconfig")
+        )
 
         msg = "Cannot patch config files: missing dependencies: gnuconfig"
         with pytest.raises(ChildError, match=msg):
@@ -300,7 +306,7 @@ def test_define(self, default_mock_concretization):
         assert define("SINGLE", "red") == "-DSINGLE:STRING=red"
 
     def test_define_from_variant(self):
-        s = Spec("cmake-client multi=up,right ~truthy single=red").concretized()
+        s = spack.concretize.concretize_one("cmake-client multi=up,right ~truthy single=red")
 
         arg = s.package.define_from_variant("MULTI")
         assert arg == "-DMULTI:STRING=right;up"

lib/spack/spack/test/builder.py

@@ -8,9 +8,9 @@
 from llnl.util.filesystem import touch
 
 import spack.builder
+import spack.concretize
 import spack.paths
 import spack.repo
-import spack.spec
 
 
 @pytest.fixture()
@@ -78,7 +78,7 @@ def builder_test_repository():
 @pytest.mark.disable_clean_stage_check
 def test_callbacks_and_installation_procedure(spec_str, expected_values, working_env):
     """Test the correct execution of callbacks and installation procedures for packages."""
-    s = spack.spec.Spec(spec_str).concretized()
+    s = spack.concretize.concretize_one(spec_str)
     builder = spack.builder.create(s.package)
     for phase_fn in builder:
         phase_fn.execute()
@@ -101,7 +101,7 @@ def test_callbacks_and_installation_procedure(spec_str, expected_values, working
     ],
 )
 def test_old_style_compatibility_with_super(spec_str, method_name, expected):
-    s = spack.spec.Spec(spec_str).concretized()
+    s = spack.concretize.concretize_one(spec_str)
     builder = spack.builder.create(s.package)
     value = getattr(builder, method_name)()
     assert value == expected
@@ -112,7 +112,7 @@ def test_old_style_compatibility_with_super(spec_str, method_name, expected):
 @pytest.mark.usefixtures("builder_test_repository", "config", "working_env")
 @pytest.mark.disable_clean_stage_check
 def test_build_time_tests_are_executed_from_default_builder():
-    s = spack.spec.Spec("old-style-autotools").concretized()
+    s = spack.concretize.concretize_one("old-style-autotools")
     builder = spack.builder.create(s.package)
     builder.pkg.run_tests = True
     for phase_fn in builder:
@@ -126,7 +126,7 @@ def test_build_time_tests_are_executed_from_default_builder():
 @pytest.mark.usefixtures("builder_test_repository", "config", "working_env")
 def test_monkey_patching_wrapped_pkg():
     """Confirm 'run_tests' is accessible through wrappers."""
-    s = spack.spec.Spec("old-style-autotools").concretized()
+    s = spack.concretize.concretize_one("old-style-autotools")
     builder = spack.builder.create(s.package)
     assert s.package.run_tests is False
     assert builder.pkg.run_tests is False
@@ -141,7 +141,7 @@ def test_monkey_patching_wrapped_pkg():
 @pytest.mark.usefixtures("builder_test_repository", "config", "working_env")
 def test_monkey_patching_test_log_file():
     """Confirm 'test_log_file' is accessible through wrappers."""
-    s = spack.spec.Spec("old-style-autotools").concretized()
+    s = spack.concretize.concretize_one("old-style-autotools")
     builder = spack.builder.create(s.package)
 
     s.package.tester.test_log_file = "/some/file"
@@ -154,7 +154,7 @@ def test_monkey_patching_test_log_file():
 @pytest.mark.not_on_windows("Does not run on windows")
 def test_install_time_test_callback(tmpdir, config, mock_packages, mock_stage):
     """Confirm able to run stand-alone test as a post-install callback."""
-    s = spack.spec.Spec("py-test-callback").concretized()
+    s = spack.concretize.concretize_one("py-test-callback")
     builder = spack.builder.create(s.package)
     builder.pkg.run_tests = True
     s.package.tester.test_log_file = tmpdir.join("install_test.log")
@@ -174,7 +174,7 @@ def test_mixins_with_builders(working_env):
     """Tests that run_after and run_before callbacks are accumulated correctly,
     when mixins are used with builders.
     """
-    s = spack.spec.Spec("builder-and-mixins").concretized()
+    s = spack.concretize.concretize_one("builder-and-mixins")
     builder = spack.builder.create(s.package)
 
     # Check that callbacks added by the mixin are in the list

lib/spack/spack/test/buildrequest.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.deptypes as dt
 import spack.installer as inst
 import spack.repo
@@ -21,8 +22,7 @@ def test_build_request_errors(install_mockery):
 
 
 def test_build_request_basics(install_mockery):
-    spec = spack.spec.Spec("dependent-install")
+    spec = spack.concretize.concretize_one("dependent-install")
-    spec.concretize()
     assert spec.concrete
 
     # Ensure key properties match expectations
@@ -39,8 +39,7 @@ def test_build_request_basics(install_mockery):
 def test_build_request_strings(install_mockery):
     """Tests of BuildRequest repr and str for coverage purposes."""
     # Using a package with one dependency
-    spec = spack.spec.Spec("dependent-install")
+    spec = spack.concretize.concretize_one("dependent-install")
-    spec.concretize()
     assert spec.concrete
 
     # Ensure key properties match expectations
@@ -72,7 +71,7 @@ def test_build_request_deptypes(
     package_deptypes,
     dependencies_deptypes,
 ):
-    s = spack.spec.Spec("dependent-install").concretized()
+    s = spack.concretize.concretize_one("dependent-install")
 
     build_request = inst.BuildRequest(
         s.package,

lib/spack/spack/test/buildtask.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.error
 import spack.installer as inst
 import spack.repo
@@ -24,7 +25,7 @@ def test_build_task_errors(install_mockery):
         inst.BuildTask(pkg_cls(spec), None)
 
     # Using a concretized package now means the request argument is checked.
-    spec.concretize()
+    spec = spack.concretize.concretize_one(spec)
     assert spec.concrete
 
     with pytest.raises(TypeError, match="is not a valid build request"):
@@ -47,8 +48,7 @@ def test_build_task_errors(install_mockery):
 
 
 def test_build_task_basics(install_mockery):
-    spec = spack.spec.Spec("dependent-install")
+    spec = spack.concretize.concretize_one("dependent-install")
-    spec.concretize()
     assert spec.concrete
 
     # Ensure key properties match expectations
@@ -69,8 +69,7 @@ def test_build_task_basics(install_mockery):
 def test_build_task_strings(install_mockery):
     """Tests of build_task repr and str for coverage purposes."""
     # Using a package with one dependency
-    spec = spack.spec.Spec("dependent-install")
+    spec = spack.concretize.concretize_one("dependent-install")
-    spec.concretize()
     assert spec.concrete
 
     # Ensure key properties match expectations

lib/spack/spack/test/ci.py

@@ -9,13 +9,12 @@
 import llnl.util.filesystem as fs
 
 import spack.ci as ci
+import spack.concretize
 import spack.environment as ev
 import spack.error
 import spack.paths as spack_paths
 import spack.repo as repo
-import spack.spec
 import spack.util.git
-from spack.spec import Spec
 
 pytestmark = [pytest.mark.usefixtures("mock_packages")]
 
@@ -54,7 +53,7 @@ def test_pipeline_dag(config, tmpdir):
     builder.add_package("pkg-a", dependencies=[("pkg-b", None, None), ("pkg-c", None, None)])
 
     with repo.use_repositories(builder.root):
-        spec_a = Spec("pkg-a").concretized()
+        spec_a = spack.concretize.concretize_one("pkg-a")
 
         key_a = ci.common.PipelineDag.key(spec_a)
         key_b = ci.common.PipelineDag.key(spec_a["pkg-b"])
@@ -449,7 +448,7 @@ def test_ci_run_standalone_tests_not_installed_junit(
     log_file = tmp_path / "junit.xml"
     args = {
         "log_file": str(log_file),
-        "job_spec": spack.spec.Spec("printing-package").concretized(),
+        "job_spec": spack.concretize.concretize_one("printing-package"),
         "repro_dir": str(repro_dir),
         "fail_fast": True,
     }
@@ -468,7 +467,7 @@ def test_ci_run_standalone_tests_not_installed_cdash(
     log_file = tmp_path / "junit.xml"
     args = {
         "log_file": str(log_file),
-        "job_spec": spack.spec.Spec("printing-package").concretized(),
+        "job_spec": spack.concretize.concretize_one("printing-package"),
         "repro_dir": str(repro_dir),
     }
 
@@ -501,7 +500,7 @@ def test_ci_run_standalone_tests_not_installed_cdash(
 def test_ci_skipped_report(tmpdir, mock_packages, config):
     """Test explicit skipping of report as well as CI's 'package' arg."""
     pkg = "trivial-smoke-test"
-    spec = spack.spec.Spec(pkg).concretized()
+    spec = spack.concretize.concretize_one(pkg)
     ci_cdash = {
         "url": "file://fake",
         "build-group": "fake-group",

lib/spack/spack/test/cmd/bootstrap.py

@@ -10,6 +10,7 @@
 
 import spack.bootstrap
 import spack.bootstrap.core
+import spack.concretize
 import spack.config
 import spack.environment as ev
 import spack.main
@@ -183,7 +184,7 @@ def test_bootstrap_mirror_metadata(mutable_config, linux_os, monkeypatch, tmpdir
     """
     old_create = spack.mirrors.utils.create
     monkeypatch.setattr(spack.mirrors.utils, "create", lambda p, s: old_create(p, []))
-    monkeypatch.setattr(spack.spec.Spec, "concretized", lambda p: p)
+    monkeypatch.setattr(spack.concretize, "concretize_one", lambda p: spack.spec.Spec(p))
 
     # Create the mirror in a temporary folder
     compilers = [

lib/spack/spack/test/cmd/buildcache.py

@@ -12,6 +12,7 @@
 
 import spack.binary_distribution
 import spack.cmd.buildcache
+import spack.concretize
 import spack.environment as ev
 import spack.error
 import spack.main
@@ -19,7 +20,6 @@
 import spack.spec
 import spack.util.url
 from spack.installer import PackageInstaller
-from spack.spec import Spec
 
 buildcache = spack.main.SpackCommand("buildcache")
 install = spack.main.SpackCommand("install")
@@ -81,7 +81,7 @@ def tests_buildcache_create(install_mockery, mock_fetch, monkeypatch, tmpdir):
 
     buildcache("push", "--unsigned", str(tmpdir), pkg)
 
-    spec = Spec(pkg).concretized()
+    spec = spack.concretize.concretize_one(pkg)
     tarball_path = spack.binary_distribution.tarball_path_name(spec, ".spack")
     tarball = spack.binary_distribution.tarball_name(spec, ".spec.json")
     assert os.path.exists(os.path.join(str(tmpdir), "build_cache", tarball_path))
@@ -101,7 +101,7 @@ def tests_buildcache_create_env(
 
         buildcache("push", "--unsigned", str(tmpdir))
 
-    spec = Spec(pkg).concretized()
+    spec = spack.concretize.concretize_one(pkg)
     tarball_path = spack.binary_distribution.tarball_path_name(spec, ".spack")
     tarball = spack.binary_distribution.tarball_name(spec, ".spec.json")
     assert os.path.exists(os.path.join(str(tmpdir), "build_cache", tarball_path))
@@ -145,7 +145,7 @@ def test_update_key_index(
 
     gpg("create", "Test Signing Key", "nobody@nowhere.com")
 
-    s = Spec("libdwarf").concretized()
+    s = spack.concretize.concretize_one("libdwarf")
 
     # Install a package
     install(s.name)
@@ -175,7 +175,7 @@ def test_buildcache_autopush(tmp_path, install_mockery, mock_fetch):
     mirror("add", "--unsigned", "mirror", mirror_dir.as_uri())
     mirror("add", "--autopush", "--unsigned", "mirror-autopush", mirror_autopush_dir.as_uri())
 
-    s = Spec("libdwarf").concretized()
+    s = spack.concretize.concretize_one("libdwarf")
 
     # Install and generate build cache index
     PackageInstaller([s.package], explicit=True).install()
@@ -219,7 +219,7 @@ def verify_mirror_contents():
             assert False
 
     # Install a package and put it in the buildcache
-    s = Spec(out_env_pkg).concretized()
+    s = spack.concretize.concretize_one(out_env_pkg)
     install(s.name)
     buildcache("push", "-u", "-f", src_mirror_url, s.name)
 
@@ -329,7 +329,7 @@ def test_buildcache_create_install(
 
     buildcache("push", "--unsigned", str(tmpdir), pkg)
 
-    spec = Spec(pkg).concretized()
+    spec = spack.concretize.concretize_one(pkg)
     tarball_path = spack.binary_distribution.tarball_path_name(spec, ".spack")
     tarball = spack.binary_distribution.tarball_name(spec, ".spec.json")
     assert os.path.exists(os.path.join(str(tmpdir), "build_cache", tarball_path))
@@ -450,7 +450,7 @@ def test_push_and_install_with_mirror_marked_unsigned_does_not_require_extra_fla
 
 
 def test_skip_no_redistribute(mock_packages, config):
-    specs = list(Spec("no-redistribute-dependent").concretized().traverse())
+    specs = list(spack.concretize.concretize_one("no-redistribute-dependent").traverse())
     filtered = spack.cmd.buildcache._skip_no_redistribute_for_public(specs)
     assert not any(s.name == "no-redistribute" for s in filtered)
     assert any(s.name == "no-redistribute-dependent" for s in filtered)
@@ -490,7 +490,7 @@ def test_push_without_build_deps(tmp_path, temporary_store, mock_packages, mutab
 
     mirror("add", "--unsigned", "my-mirror", str(tmp_path))
 
-    s = spack.spec.Spec("dtrun3").concretized()
+    s = spack.concretize.concretize_one("dtrun3")
     PackageInstaller([s.package], explicit=True, fake=True).install()
     s["dtbuild3"].package.do_uninstall()
 

lib/spack/spack/test/cmd/checksum.py

@@ -7,10 +7,10 @@
 import pytest
 
 import spack.cmd.checksum
+import spack.concretize
 import spack.error
 import spack.package_base
 import spack.repo
-import spack.spec
 import spack.stage
 import spack.util.web
 from spack.main import SpackCommand
@@ -308,7 +308,7 @@ def test_checksum_url(mock_packages, config):
 
 
 def test_checksum_verification_fails(default_mock_concretization, capsys, can_fetch_versions):
-    spec = spack.spec.Spec("zlib").concretized()
+    spec = spack.concretize.concretize_one("zlib")
     pkg = spec.package
     versions = list(pkg.versions.keys())
     version_hashes = {versions[0]: "abadhash", Version("0.1"): "123456789"}

lib/spack/spack/test/cmd/ci.py

@@ -18,6 +18,7 @@
 import spack.ci as ci
 import spack.cmd
 import spack.cmd.ci
+import spack.concretize
 import spack.environment as ev
 import spack.hash_types as ht
 import spack.main
@@ -1056,7 +1057,7 @@ def test_ci_rebuild_index(
     with working_dir(tmp_path):
         env_cmd("create", "test", "./spack.yaml")
         with ev.read("test"):
-            concrete_spec = Spec("callpath").concretized()
+            concrete_spec = spack.concretize.concretize_one("callpath")
             with open(tmp_path / "spec.json", "w", encoding="utf-8") as f:
                 f.write(concrete_spec.to_json(hash=ht.dag_hash))
 
@@ -1177,12 +1178,10 @@ def test_ci_generate_read_broken_specs_url(
     ci_base_environment,
 ):
     """Verify that `broken-specs-url` works as intended"""
-    spec_a = Spec("pkg-a")
+    spec_a = spack.concretize.concretize_one("pkg-a")
-    spec_a.concretize()
     a_dag_hash = spec_a.dag_hash()
 
-    spec_flattendeps = Spec("flatten-deps")
+    spec_flattendeps = spack.concretize.concretize_one("flatten-deps")
-    spec_flattendeps.concretize()
     flattendeps_dag_hash = spec_flattendeps.dag_hash()
 
     broken_specs_url = tmp_path.as_uri()
@@ -1533,8 +1532,7 @@ def dynamic_mapping_setup(tmpdir):
 """
         )
 
-    spec_a = Spec("pkg-a")
+    spec_a = spack.concretize.concretize_one("pkg-a")
-    spec_a.concretize()
 
     return gitlab_generator.get_job_name(spec_a)
 

lib/spack/spack/test/cmd/clean.py

@@ -10,10 +10,8 @@
 
 import spack.caches
 import spack.cmd.clean
-import spack.environment as ev
 import spack.main
 import spack.package_base
-import spack.spec
 import spack.stage
 import spack.store
 
@@ -69,20 +67,6 @@ def test_function_calls(command_line, effects, mock_calls_for_clean):
         assert mock_calls_for_clean[name] == (1 if name in effects else 0)
 
 
-def test_env_aware_clean(mock_stage, install_mockery, mutable_mock_env_path, monkeypatch):
-    e = ev.create("test", with_view=False)
-    e.add("mpileaks")
-    e.concretize()
-
-    def fail(*args, **kwargs):
-        raise Exception("This should not have been called")
-
-    monkeypatch.setattr(spack.spec.Spec, "concretize", fail)
-
-    with e:
-        clean("mpileaks")
-
-
 def test_remove_python_cache(tmpdir, monkeypatch):
     cache_files = ["file1.pyo", "file2.pyc"]
     source_file = "file1.py"

lib/spack/spack/test/cmd/config.py

@@ -8,12 +8,12 @@
 
 import llnl.util.filesystem as fs
 
+import spack.concretize
 import spack.config
 import spack.database
 import spack.environment as ev
 import spack.main
 import spack.schema.config
-import spack.spec
 import spack.store
 import spack.util.spack_yaml as syaml
 
@@ -593,8 +593,7 @@ def test_config_prefer_upstream(
     prepared_db = spack.database.Database(mock_db_root, layout=gen_mock_layout("/a/"))
 
     for spec in ["hdf5 +mpi", "hdf5 ~mpi", "boost+debug~icu+graph", "dependency-install", "patch"]:
-        dep = spack.spec.Spec(spec)
+        dep = spack.concretize.concretize_one(spec)
-        dep.concretize()
         prepared_db.add(dep)
 
     downstream_db_root = str(tmpdir_factory.mktemp("mock_downstream_db_root"))

lib/spack/spack/test/cmd/deprecate.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.spec
 import spack.store
 from spack.enums import InstallRecordStatus
@@ -66,8 +67,8 @@ def test_deprecate_deps(mock_packages, mock_archive, mock_fetch, install_mockery
     install("libdwarf@20130729 ^libelf@0.8.13")
     install("libdwarf@20130207 ^libelf@0.8.10")
 
-    new_spec = spack.spec.Spec("libdwarf@20130729^libelf@0.8.13").concretized()
+    new_spec = spack.concretize.concretize_one("libdwarf@20130729^libelf@0.8.13")
-    old_spec = spack.spec.Spec("libdwarf@20130207^libelf@0.8.10").concretized()
+    old_spec = spack.concretize.concretize_one("libdwarf@20130207^libelf@0.8.10")
 
     all_installed = spack.store.STORE.db.query()
 
@@ -107,12 +108,12 @@ def test_deprecate_already_deprecated(mock_packages, mock_archive, mock_fetch, i
     install("libelf@0.8.12")
     install("libelf@0.8.10")
 
-    deprecated_spec = spack.spec.Spec("libelf@0.8.10").concretized()
+    deprecated_spec = spack.concretize.concretize_one("libelf@0.8.10")
 
     deprecate("-y", "libelf@0.8.10", "libelf@0.8.12")
 
     deprecator = spack.store.STORE.db.deprecator(deprecated_spec)
-    assert deprecator == spack.spec.Spec("libelf@0.8.12").concretized()
+    assert deprecator == spack.concretize.concretize_one("libelf@0.8.12")
 
     deprecate("-y", "libelf@0.8.10", "libelf@0.8.13")
 
@@ -122,7 +123,7 @@ def test_deprecate_already_deprecated(mock_packages, mock_archive, mock_fetch, i
     assert len(all_available) == 3
 
     deprecator = spack.store.STORE.db.deprecator(deprecated_spec)
-    assert deprecator == spack.spec.Spec("libelf@0.8.13").concretized()
+    assert deprecator == spack.concretize.concretize_one("libelf@0.8.13")
 
 
 def test_deprecate_deprecator(mock_packages, mock_archive, mock_fetch, install_mockery):
@@ -132,9 +133,9 @@ def test_deprecate_deprecator(mock_packages, mock_archive, mock_fetch, install_m
     install("libelf@0.8.12")
     install("libelf@0.8.10")
 
-    first_deprecated_spec = spack.spec.Spec("libelf@0.8.10").concretized()
+    first_deprecated_spec = spack.concretize.concretize_one("libelf@0.8.10")
-    second_deprecated_spec = spack.spec.Spec("libelf@0.8.12").concretized()
+    second_deprecated_spec = spack.concretize.concretize_one("libelf@0.8.12")
-    final_deprecator = spack.spec.Spec("libelf@0.8.13").concretized()
+    final_deprecator = spack.concretize.concretize_one("libelf@0.8.13")
 
     deprecate("-y", "libelf@0.8.10", "libelf@0.8.12")
 
@@ -164,7 +165,7 @@ def test_concretize_deprecated(mock_packages, mock_archive, mock_fetch, install_
 
     spec = spack.spec.Spec("libelf@0.8.10")
     with pytest.raises(spack.spec.SpecDeprecatedError):
-        spec.concretize()
+        spack.concretize.concretize_one(spec)
 
 
 @pytest.mark.usefixtures("mock_packages", "mock_archive", "mock_fetch", "install_mockery")

lib/spack/spack/test/cmd/dev_build.py

@@ -8,6 +8,7 @@
 
 import llnl.util.filesystem as fs
 
+import spack.concretize
 import spack.environment as ev
 import spack.error
 import spack.repo
@@ -23,7 +24,9 @@
 
 
 def test_dev_build_basics(tmpdir, install_mockery):
-    spec = spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}").concretized()
+    spec = spack.concretize.concretize_one(
+        spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}")
+    )
 
     assert "dev_path" in spec.variants
 
@@ -41,7 +44,9 @@ def test_dev_build_basics(tmpdir, install_mockery):
 
 
 def test_dev_build_before(tmpdir, install_mockery):
-    spec = spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}").concretized()
+    spec = spack.concretize.concretize_one(
+        spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}")
+    )
 
     with tmpdir.as_cwd():
         with open(spec.package.filename, "w", encoding="utf-8") as f:
@@ -57,7 +62,9 @@ def test_dev_build_before(tmpdir, install_mockery):
 
 
 def test_dev_build_until(tmpdir, install_mockery):
-    spec = spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}").concretized()
+    spec = spack.concretize.concretize_one(
+        spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}")
+    )
 
     with tmpdir.as_cwd():
         with open(spec.package.filename, "w", encoding="utf-8") as f:
@@ -75,7 +82,9 @@ def test_dev_build_until(tmpdir, install_mockery):
 
 def test_dev_build_until_last_phase(tmpdir, install_mockery):
     # Test that we ignore the last_phase argument if it is already last
-    spec = spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}").concretized()
+    spec = spack.concretize.concretize_one(
+        spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}")
+    )
 
     with tmpdir.as_cwd():
         with open(spec.package.filename, "w", encoding="utf-8") as f:
@@ -93,7 +102,9 @@ def test_dev_build_until_last_phase(tmpdir, install_mockery):
 
 
 def test_dev_build_before_until(tmpdir, install_mockery):
-    spec = spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}").concretized()
+    spec = spack.concretize.concretize_one(
+        spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={tmpdir}")
+    )
 
     with tmpdir.as_cwd():
         with open(spec.package.filename, "w", encoding="utf-8") as f:
@@ -129,8 +140,9 @@ def test_dev_build_drop_in(tmpdir, mock_packages, monkeypatch, install_mockery,
 
 
 def test_dev_build_fails_already_installed(tmpdir, install_mockery):
-    spec = spack.spec.Spec("dev-build-test-install@0.0.0 dev_path=%s" % tmpdir)
+    spec = spack.concretize.concretize_one(
-    spec.concretize()
+        spack.spec.Spec("dev-build-test-install@0.0.0 dev_path=%s" % tmpdir)
+    )
 
     with tmpdir.as_cwd():
         with open(spec.package.filename, "w", encoding="utf-8") as f:
@@ -172,8 +184,9 @@ def test_dev_build_env(tmpdir, install_mockery, mutable_mock_env_path):
     """Test Spack does dev builds for packages in develop section of env."""
     # setup dev-build-test-install package for dev build
     build_dir = tmpdir.mkdir("build")
-    spec = spack.spec.Spec("dev-build-test-install@0.0.0 dev_path=%s" % build_dir)
+    spec = spack.concretize.concretize_one(
-    spec.concretize()
+        spack.spec.Spec("dev-build-test-install@0.0.0 dev_path=%s" % build_dir)
+    )
 
     with build_dir.as_cwd():
         with open(spec.package.filename, "w", encoding="utf-8") as f:
@@ -208,8 +221,9 @@ def test_dev_build_env_with_vars(tmpdir, install_mockery, mutable_mock_env_path,
     """Test Spack does dev builds for packages in develop section of env (path with variables)."""
     # setup dev-build-test-install package for dev build
     build_dir = tmpdir.mkdir("build")
-    spec = spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={build_dir}")
+    spec = spack.concretize.concretize_one(
-    spec.concretize()
+        spack.spec.Spec(f"dev-build-test-install@0.0.0 dev_path={build_dir}")
+    )
 
     # store the build path in an environment variable that will be used in the environment
     monkeypatch.setenv("CUSTOM_BUILD_PATH", build_dir)
@@ -246,8 +260,9 @@ def test_dev_build_env_version_mismatch(tmpdir, install_mockery, mutable_mock_en
     """Test Spack constraints concretization by develop specs."""
     # setup dev-build-test-install package for dev build
     build_dir = tmpdir.mkdir("build")
-    spec = spack.spec.Spec("dev-build-test-install@0.0.0 dev_path=%s" % tmpdir)
+    spec = spack.concretize.concretize_one(
-    spec.concretize()
+        spack.spec.Spec("dev-build-test-install@0.0.0 dev_path=%s" % tmpdir)
+    )
 
     with build_dir.as_cwd():
         with open(spec.package.filename, "w", encoding="utf-8") as f:
@@ -327,8 +342,8 @@ def test_dev_build_multiple(tmpdir, install_mockery, mutable_mock_env_path, mock
         with ev.read("test"):
             # Do concretization inside environment for dev info
             # These specs are the source of truth to compare against the installs
-            leaf_spec.concretize()
+            leaf_spec = spack.concretize.concretize_one(leaf_spec)
-            root_spec.concretize()
+            root_spec = spack.concretize.concretize_one(root_spec)
 
             # Do install
             install()
@@ -374,8 +389,8 @@ def test_dev_build_env_dependency(tmpdir, install_mockery, mock_fetch, mutable_m
             # concretize in the environment to get the dev build info
             # equivalent to setting dev_build and dev_path variants
             # on all specs above
-            spec.concretize()
+            spec = spack.concretize.concretize_one(spec)
-            dep_spec.concretize()
+            dep_spec = spack.concretize.concretize_one(dep_spec)
             install()
 
     # Ensure that both specs installed properly
@@ -399,8 +414,9 @@ def test_dev_build_rebuild_on_source_changes(
     """
     # setup dev-build-test-install package for dev build
     build_dir = tmpdir.mkdir("build")
-    spec = spack.spec.Spec("dev-build-test-install@0.0.0 dev_path=%s" % build_dir)
+    spec = spack.concretize.concretize_one(
-    spec.concretize()
+        spack.spec.Spec("dev-build-test-install@0.0.0 dev_path=%s" % build_dir)
+    )
 
     def reset_string():
         with build_dir.as_cwd():

lib/spack/spack/test/cmd/develop.py

@@ -8,6 +8,7 @@
 
 import llnl.util.filesystem as fs
 
+import spack.concretize
 import spack.config
 import spack.environment as ev
 import spack.package_base
@@ -138,7 +139,8 @@ def check_path(stage, dest):
             self.check_develop(e, spack.spec.Spec("mpich@=1.0"), path)
 
             # Check modifications actually worked
-            assert spack.spec.Spec("mpich@1.0").concretized().satisfies("dev_path=%s" % abspath)
+            result = spack.concretize.concretize_one("mpich@1.0")
+            assert result.satisfies("dev_path=%s" % abspath)
 
     def test_develop_canonicalize_path_no_args(self, monkeypatch):
         env("create", "test")
@@ -165,7 +167,8 @@ def check_path(stage, dest):
             self.check_develop(e, spack.spec.Spec("mpich@=1.0"), path)
 
             # Check modifications actually worked
-            assert spack.spec.Spec("mpich@1.0").concretized().satisfies("dev_path=%s" % abspath)
+            result = spack.concretize.concretize_one("mpich@1.0")
+            assert result.satisfies("dev_path=%s" % abspath)
 
 
 def _git_commit_list(git_repo_dir):
@@ -190,7 +193,7 @@ def test_develop_full_git_repo(
         spack.package_base.PackageBase, "git", "file://%s" % repo_path, raising=False
     )
 
-    spec = spack.spec.Spec("git-test-commit@1.2").concretized()
+    spec = spack.concretize.concretize_one("git-test-commit@1.2")
     try:
         spec.package.do_stage()
         commits = _git_commit_list(spec.package.stage[0].source_path)

lib/spack/spack/test/cmd/diff.py

@@ -5,9 +5,9 @@
 import pytest
 
 import spack.cmd.diff
+import spack.concretize
 import spack.main
 import spack.repo
-import spack.spec
 import spack.util.spack_json as sjson
 from spack.test.conftest import create_test_repo
 
@@ -133,8 +133,8 @@ def test_repo(_create_test_repo, monkeypatch, mock_stage):
 
 
 def test_diff_ignore(test_repo):
-    specA = spack.spec.Spec("p1+usev1").concretized()
+    specA = spack.concretize.concretize_one("p1+usev1")
-    specB = spack.spec.Spec("p1~usev1").concretized()
+    specB = spack.concretize.concretize_one("p1~usev1")
 
     c1 = spack.cmd.diff.compare_specs(specA, specB, to_string=False)
 
@@ -154,8 +154,8 @@ def find(function_list, name, args):
 
     # Check ignoring changes on multiple packages
 
-    specA = spack.spec.Spec("p1+usev1 ^p3+p3var").concretized()
+    specA = spack.concretize.concretize_one("p1+usev1 ^p3+p3var")
-    specA = spack.spec.Spec("p1~usev1 ^p3~p3var").concretized()
+    specA = spack.concretize.concretize_one("p1~usev1 ^p3~p3var")
 
     c3 = spack.cmd.diff.compare_specs(specA, specB, to_string=False)
     assert find(c3["a_not_b"], "variant_value", ["p3", "p3var"])
@@ -168,8 +168,8 @@ def find(function_list, name, args):
 def test_diff_cmd(install_mockery, mock_fetch, mock_archive, mock_packages):
     """Test that we can install two packages and diff them"""
 
-    specA = spack.spec.Spec("mpileaks").concretized()
+    specA = spack.concretize.concretize_one("mpileaks")
-    specB = spack.spec.Spec("mpileaks+debug").concretized()
+    specB = spack.concretize.concretize_one("mpileaks+debug")
 
     # Specs should be the same as themselves
     c = spack.cmd.diff.compare_specs(specA, specA, to_string=True)

lib/spack/spack/test/cmd/env.py

@@ -19,6 +19,7 @@
 from llnl.util.symlink import readlink
 
 import spack.cmd.env
+import spack.concretize
 import spack.config
 import spack.environment as ev
 import spack.environment.depfile as depfile
@@ -957,7 +958,7 @@ def test_lockfile_spliced_specs(environment_from_manifest, install_mockery):
     """Test that an environment can round-trip a spliced spec."""
     # Create a local install for zmpi to splice in
     # Default concretization is not using zmpi
-    zmpi = spack.spec.Spec("zmpi").concretized()
+    zmpi = spack.concretize.concretize_one("zmpi")
     PackageInstaller([zmpi.package], fake=True).install()
 
     e1 = environment_from_manifest(
@@ -1320,39 +1321,43 @@ def test_config_change_existing(mutable_mock_env_path, tmp_path, mock_packages,
     with e:
         # List of requirements, flip a variant
         config("change", "packages:mpich:require:~debug")
-        test_spec = spack.spec.Spec("mpich").concretized()
+        test_spec = spack.concretize.concretize_one("mpich")
         assert test_spec.satisfies("@3.0.2~debug")
 
         # List of requirements, change the version (in a different scope)
         config("change", "packages:mpich:require:@3.0.3")
-        test_spec = spack.spec.Spec("mpich").concretized()
+        test_spec = spack.concretize.concretize_one("mpich")
         assert test_spec.satisfies("@3.0.3")
 
         # "require:" as a single string, also try specifying
         # a spec string that requires enclosing in quotes as
         # part of the config path
         config("change", 'packages:libelf:require:"@0.8.12:"')
-        spack.spec.Spec("libelf@0.8.12").concretized()
+        spack.concretize.concretize_one("libelf@0.8.12")
         # No need for assert, if there wasn't a failure, we
         # changed the requirement successfully.
 
         # Use change to add a requirement for a package that
         # has no requirements defined
         config("change", "packages:fftw:require:+mpi")
-        test_spec = spack.spec.Spec("fftw").concretized()
+        test_spec = spack.concretize.concretize_one("fftw")
         assert test_spec.satisfies("+mpi")
         config("change", "packages:fftw:require:~mpi")
-        test_spec = spack.spec.Spec("fftw").concretized()
+        test_spec = spack.concretize.concretize_one("fftw")
         assert test_spec.satisfies("~mpi")
         config("change", "packages:fftw:require:@1.0")
-        test_spec = spack.spec.Spec("fftw").concretized()
+        test_spec = spack.concretize.concretize_one("fftw")
         assert test_spec.satisfies("@1.0~mpi")
 
         # Use "--match-spec" to change one spec in a "one_of"
         # list
         config("change", "packages:bowtie:require:@1.2.2", "--match-spec", "@1.2.0")
-        spack.spec.Spec("bowtie@1.3.0").concretize()
+        # confirm that we can concretize to either value
-        spack.spec.Spec("bowtie@1.2.2").concretized()
+        spack.concretize.concretize_one("bowtie@1.3.0")
+        spack.concretize.concretize_one("bowtie@1.2.2")
+        # confirm that we cannot concretize to the old value
+        with pytest.raises(spack.solver.asp.UnsatisfiableSpecError):
+            spack.concretize.concretize_one("bowtie@1.2.0")
 
 
 def test_config_change_new(mutable_mock_env_path, tmp_path, mock_packages, mutable_config):
@@ -1367,8 +1372,8 @@ def test_config_change_new(mutable_mock_env_path, tmp_path, mock_packages, mutab
     with ev.Environment(tmp_path):
         config("change", "packages:mpich:require:~debug")
         with pytest.raises(spack.solver.asp.UnsatisfiableSpecError):
-            spack.spec.Spec("mpich+debug").concretized()
+            spack.concretize.concretize_one("mpich+debug")
-        spack.spec.Spec("mpich~debug").concretized()
+        spack.concretize.concretize_one("mpich~debug")
 
     # Now check that we raise an error if we need to add a require: constraint
     # when preexisting config manually specified it as a singular spec
@@ -1382,7 +1387,7 @@ def test_config_change_new(mutable_mock_env_path, tmp_path, mock_packages, mutab
 """
     )
     with ev.Environment(tmp_path):
-        assert spack.spec.Spec("mpich").concretized().satisfies("@3.0.3")
+        assert spack.concretize.concretize_one("mpich").satisfies("@3.0.3")
         with pytest.raises(spack.error.ConfigError, match="not a list"):
             config("change", "packages:mpich:require:~debug")
 
@@ -1690,7 +1695,7 @@ def test_stage(mock_stage, mock_fetch, install_mockery):
     root = str(mock_stage)
 
     def check_stage(spec):
-        spec = Spec(spec).concretized()
+        spec = spack.concretize.concretize_one(spec)
         for dep in spec.traverse():
             stage_name = f"{stage_prefix}{dep.name}-{dep.version}-{dep.dag_hash()}"
             assert os.path.isdir(os.path.join(root, stage_name))
@@ -1791,7 +1796,7 @@ def test_indirect_build_dep(tmp_path):
 
     with spack.repo.use_repositories(builder.root):
         x_spec = Spec("x")
-        x_concretized = x_spec.concretized()
+        x_concretized = spack.concretize.concretize_one(x_spec)
 
         _env_create("test", with_view=False)
         e = ev.read("test")
@@ -1824,10 +1829,10 @@ def test_store_different_build_deps(tmp_path):
 
     with spack.repo.use_repositories(builder.root):
         y_spec = Spec("y ^z@3")
-        y_concretized = y_spec.concretized()
+        y_concretized = spack.concretize.concretize_one(y_spec)
 
         x_spec = Spec("x ^z@2")
-        x_concretized = x_spec.concretized()
+        x_concretized = spack.concretize.concretize_one(x_spec)
 
         # Even though x chose a different 'z', the y it chooses should be identical
         # *aside* from the dependency on 'z'.  The dag_hash() will show the difference

lib/spack/spack/test/cmd/extensions.py

@@ -5,16 +5,18 @@
 
 import pytest
 
+import spack.concretize
 from spack.installer import PackageInstaller
 from spack.main import SpackCommand, SpackCommandError
-from spack.spec import Spec
 
 extensions = SpackCommand("extensions")
 
 
 @pytest.fixture
 def python_database(mock_packages, mutable_database):
-    specs = [Spec(s).concretized() for s in ["python", "py-extension1", "py-extension2"]]
+    specs = [
+        spack.concretize.concretize_one(s) for s in ["python", "py-extension1", "py-extension2"]
+    ]
     PackageInstaller([s.package for s in specs], explicit=True, fake=True).install()
     yield
 
@@ -22,7 +24,7 @@ def python_database(mock_packages, mutable_database):
 @pytest.mark.not_on_windows("All Fetchers Failed")
 @pytest.mark.db
 def test_extensions(mock_packages, python_database, capsys):
-    ext2 = Spec("py-extension2").concretized()
+    ext2 = spack.concretize.concretize_one("py-extension2")
 
     def check_output(ni):
         with capsys.disabled():

lib/spack/spack/test/cmd/find.py

@@ -12,13 +12,13 @@
 
 import spack.cmd as cmd
 import spack.cmd.find
+import spack.concretize
 import spack.environment as ev
 import spack.repo
 import spack.store
 import spack.user_environment as uenv
 from spack.enums import InstallRecordStatus
 from spack.main import SpackCommand
-from spack.spec import Spec
 from spack.test.conftest import create_test_repo
 from spack.test.utilities import SpackCommandArgs
 from spack.util.pattern import Bunch
@@ -201,7 +201,8 @@ def test_find_json_deps(database):
 @pytest.mark.db
 def test_display_json(database, capsys):
     specs = [
-        Spec(s).concretized() for s in ["mpileaks ^zmpi", "mpileaks ^mpich", "mpileaks ^mpich2"]
+        spack.concretize.concretize_one(s)
+        for s in ["mpileaks ^zmpi", "mpileaks ^mpich", "mpileaks ^mpich2"]
     ]
 
     cmd.display_specs_as_json(specs)
@@ -216,7 +217,8 @@ def test_display_json(database, capsys):
 @pytest.mark.db
 def test_display_json_deps(database, capsys):
     specs = [
-        Spec(s).concretized() for s in ["mpileaks ^zmpi", "mpileaks ^mpich", "mpileaks ^mpich2"]
+        spack.concretize.concretize_one(s)
+        for s in ["mpileaks ^zmpi", "mpileaks ^mpich", "mpileaks ^mpich2"]
     ]
 
     cmd.display_specs_as_json(specs, deps=True)
@@ -275,7 +277,7 @@ def test_find_format_deps(database, config):
 def test_find_format_deps_paths(database, config):
     output = find("-dp", "--format", "{name}-{version}", "mpileaks", "^zmpi")
 
-    spec = Spec("mpileaks ^zmpi").concretized()
+    spec = spack.concretize.concretize_one("mpileaks ^zmpi")
     prefixes = [s.prefix for s in spec.traverse()]
 
     assert (
@@ -300,7 +302,8 @@ def test_find_very_long(database, config):
     output = find("-L", "--no-groups", "mpileaks")
 
     specs = [
-        Spec(s).concretized() for s in ["mpileaks ^zmpi", "mpileaks ^mpich", "mpileaks ^mpich2"]
+        spack.concretize.concretize_one(s)
+        for s in ["mpileaks ^zmpi", "mpileaks ^mpich", "mpileaks ^mpich2"]
     ]
 
     assert set(output.strip().split("\n")) == set(

lib/spack/spack/test/cmd/gc.py

@@ -5,6 +5,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.deptypes as dt
 import spack.environment as ev
 import spack.main
@@ -25,8 +26,7 @@ def test_gc_without_build_dependency(mutable_database):
 
 @pytest.mark.db
 def test_gc_with_build_dependency(mutable_database):
-    s = spack.spec.Spec("simple-inheritance")
+    s = spack.concretize.concretize_one("simple-inheritance")
-    s.concretize()
     PackageInstaller([s.package], explicit=True, fake=True).install()
 
     assert "There are no unused specs." in gc("-yb")
@@ -36,8 +36,8 @@ def test_gc_with_build_dependency(mutable_database):
 
 @pytest.mark.db
 def test_gc_with_constraints(mutable_database):
-    s_cmake1 = spack.spec.Spec("simple-inheritance ^cmake@3.4.3").concretized()
+    s_cmake1 = spack.concretize.concretize_one("simple-inheritance ^cmake@3.4.3")
-    s_cmake2 = spack.spec.Spec("simple-inheritance ^cmake@3.23.1").concretized()
+    s_cmake2 = spack.concretize.concretize_one("simple-inheritance ^cmake@3.23.1")
     PackageInstaller([s_cmake1.package], explicit=True, fake=True).install()
     PackageInstaller([s_cmake2.package], explicit=True, fake=True).install()
 
@@ -52,8 +52,7 @@ def test_gc_with_constraints(mutable_database):
 
 @pytest.mark.db
 def test_gc_with_environment(mutable_database, mutable_mock_env_path):
-    s = spack.spec.Spec("simple-inheritance")
+    s = spack.concretize.concretize_one("simple-inheritance")
-    s.concretize()
     PackageInstaller([s.package], explicit=True, fake=True).install()
 
     e = ev.create("test_gc")
@@ -68,8 +67,7 @@ def test_gc_with_environment(mutable_database, mutable_mock_env_path):
 
 @pytest.mark.db
 def test_gc_with_build_dependency_in_environment(mutable_database, mutable_mock_env_path):
-    s = spack.spec.Spec("simple-inheritance")
+    s = spack.concretize.concretize_one("simple-inheritance")
-    s.concretize()
     PackageInstaller([s.package], explicit=True, fake=True).install()
 
     e = ev.create("test_gc")
@@ -120,8 +118,7 @@ def test_gc_except_any_environments(mutable_database, mutable_mock_env_path):
 
 @pytest.mark.db
 def test_gc_except_specific_environments(mutable_database, mutable_mock_env_path):
-    s = spack.spec.Spec("simple-inheritance")
+    s = spack.concretize.concretize_one("simple-inheritance")
-    s.concretize()
     PackageInstaller([s.package], explicit=True, fake=True).install()
 
     assert mutable_database.query_local("zmpi")
@@ -147,8 +144,7 @@ def test_gc_except_nonexisting_dir_env(mutable_database, mutable_mock_env_path,
 
 @pytest.mark.db
 def test_gc_except_specific_dir_env(mutable_database, mutable_mock_env_path, tmpdir):
-    s = spack.spec.Spec("simple-inheritance")
+    s = spack.concretize.concretize_one("simple-inheritance")
-    s.concretize()
     PackageInstaller([s.package], explicit=True, fake=True).install()
 
     assert mutable_database.query_local("zmpi")

lib/spack/spack/test/cmd/install.py

@@ -19,6 +19,7 @@
 import spack.build_environment
 import spack.cmd.common.arguments
 import spack.cmd.install
+import spack.concretize
 import spack.config
 import spack.environment as ev
 import spack.error
@@ -134,7 +135,7 @@ def test_package_output(tmpdir, capsys, install_mockery, mock_fetch):
     # we can't use output capture here because it interferes with Spack's
     # logging. TODO: see whether we can get multiple log_outputs to work
     # when nested AND in pytest
-    spec = Spec("printing-package").concretized()
+    spec = spack.concretize.concretize_one("printing-package")
     pkg = spec.package
     PackageInstaller([pkg], explicit=True, verbose=True).install()
 
@@ -174,7 +175,7 @@ def test_install_output_on_python_error(mock_packages, mock_archive, mock_fetch,
 def test_install_with_source(mock_packages, mock_archive, mock_fetch, install_mockery):
     """Verify that source has been copied into place."""
     install("--source", "--keep-stage", "trivial-install-test-package")
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
     src = os.path.join(spec.prefix.share, "trivial-install-test-package", "src")
     assert filecmp.cmp(
         os.path.join(mock_archive.path, "configure"), os.path.join(src, "configure")
@@ -182,8 +183,7 @@ def test_install_with_source(mock_packages, mock_archive, mock_fetch, install_mo
 
 
 def test_install_env_variables(mock_packages, mock_archive, mock_fetch, install_mockery):
-    spec = Spec("libdwarf")
+    spec = spack.concretize.concretize_one("libdwarf")
-    spec.concretize()
     install("libdwarf")
     assert os.path.isfile(spec.package.install_env_path)
 
@@ -204,8 +204,7 @@ def test_show_log_on_error(mock_packages, mock_archive, mock_fetch, install_mock
 
 def test_install_overwrite(mock_packages, mock_archive, mock_fetch, install_mockery):
     # Try to install a spec and then to reinstall it.
-    spec = Spec("libdwarf")
+    spec = spack.concretize.concretize_one("libdwarf")
-    spec.concretize()
 
     install("libdwarf")
 
@@ -238,8 +237,7 @@ def test_install_overwrite(mock_packages, mock_archive, mock_fetch, install_mock
 
 def test_install_overwrite_not_installed(mock_packages, mock_archive, mock_fetch, install_mockery):
     # Try to install a spec and then to reinstall it.
-    spec = Spec("libdwarf")
+    spec = spack.concretize.concretize_one("libdwarf")
-    spec.concretize()
 
     assert not os.path.exists(spec.prefix)
 
@@ -260,7 +258,7 @@ def test_install_commit(mock_git_version_info, install_mockery, mock_packages, m
     monkeypatch.setattr(spack.package_base.PackageBase, "git", file_url, raising=False)
 
     # Use the earliest commit in the respository
-    spec = Spec(f"git-test-commit@{commits[-1]}").concretized()
+    spec = spack.concretize.concretize_one(f"git-test-commit@{commits[-1]}")
     PackageInstaller([spec.package], explicit=True).install()
 
     # Ensure first commit file contents were written
@@ -273,13 +271,11 @@ def test_install_commit(mock_git_version_info, install_mockery, mock_packages, m
 
 def test_install_overwrite_multiple(mock_packages, mock_archive, mock_fetch, install_mockery):
     # Try to install a spec and then to reinstall it.
-    libdwarf = Spec("libdwarf")
+    libdwarf = spack.concretize.concretize_one("libdwarf")
-    libdwarf.concretize()
 
     install("libdwarf")
 
-    cmake = Spec("cmake")
+    cmake = spack.concretize.concretize_one("cmake")
-    cmake.concretize()
 
     install("cmake")
 
@@ -355,7 +351,7 @@ def test_install_invalid_spec():
 )
 def test_install_from_file(spec, concretize, error_code, tmpdir):
     if concretize:
-        spec.concretize()
+        spec = spack.concretize.concretize_one(spec)
 
     specfile = tmpdir.join("spec.yaml")
 
@@ -485,8 +481,7 @@ def test_install_mix_cli_and_files(clispecs, filespecs, tmpdir):
     for spec in filespecs:
         filepath = tmpdir.join(spec + ".yaml")
         args = ["-f", str(filepath)] + args
-        s = Spec(spec)
+        s = spack.concretize.concretize_one(spec)
-        s.concretize()
         with filepath.open("w") as f:
             s.to_yaml(f)
 
@@ -495,8 +490,7 @@ def test_install_mix_cli_and_files(clispecs, filespecs, tmpdir):
 
 
 def test_extra_files_are_archived(mock_packages, mock_archive, mock_fetch, install_mockery):
-    s = Spec("archive-files")
+    s = spack.concretize.concretize_one("archive-files")
-    s.concretize()
 
     install("archive-files")
 
@@ -615,8 +609,7 @@ def test_cdash_install_from_spec_json(
     with capfd.disabled(), tmpdir.as_cwd():
         spec_json_path = str(tmpdir.join("spec.json"))
 
-        pkg_spec = Spec("pkg-a")
+        pkg_spec = spack.concretize.concretize_one("pkg-a")
-        pkg_spec.concretize()
 
         with open(spec_json_path, "w", encoding="utf-8") as fd:
             fd.write(pkg_spec.to_json(hash=ht.dag_hash))
@@ -692,8 +685,8 @@ def test_cache_only_fails(tmpdir, mock_fetch, install_mockery, capfd):
 
 
 def test_install_only_dependencies(tmpdir, mock_fetch, install_mockery):
-    dep = Spec("dependency-install").concretized()
+    dep = spack.concretize.concretize_one("dependency-install")
-    root = Spec("dependent-install").concretized()
+    root = spack.concretize.concretize_one("dependent-install")
 
     install("--only", "dependencies", "dependent-install")
 
@@ -714,8 +707,8 @@ def test_install_only_package(tmpdir, mock_fetch, install_mockery, capfd):
 
 
 def test_install_deps_then_package(tmpdir, mock_fetch, install_mockery):
-    dep = Spec("dependency-install").concretized()
+    dep = spack.concretize.concretize_one("dependency-install")
-    root = Spec("dependent-install").concretized()
+    root = spack.concretize.concretize_one("dependent-install")
 
     install("--only", "dependencies", "dependent-install")
     assert os.path.exists(dep.prefix)
@@ -733,8 +726,8 @@ def test_install_only_dependencies_in_env(
     env("create", "test")
 
     with ev.read("test"):
-        dep = Spec("dependency-install").concretized()
+        dep = spack.concretize.concretize_one("dependency-install")
-        root = Spec("dependent-install").concretized()
+        root = spack.concretize.concretize_one("dependent-install")
 
         install("-v", "--only", "dependencies", "--add", "dependent-install")
 
@@ -750,8 +743,8 @@ def test_install_only_dependencies_of_all_in_env(
 
     with ev.read("test"):
         roots = [
-            Spec("dependent-install@1.0").concretized(),
+            spack.concretize.concretize_one("dependent-install@1.0"),
-            Spec("dependent-install@2.0").concretized(),
+            spack.concretize.concretize_one("dependent-install@2.0"),
         ]
 
         add("dependent-install@1.0")
@@ -900,7 +893,7 @@ def test_cdash_configure_warning(tmpdir, mock_fetch, install_mockery, capfd):
 
         # Ensure that even on non-x86_64 architectures, there are no
         # dependencies installed
-        spec = Spec("configure-warning").concretized()
+        spec = spack.concretize.concretize_one("configure-warning")
         spec.clear_dependencies()
         specfile = "./spec.json"
         with open(specfile, "w", encoding="utf-8") as f:
@@ -946,7 +939,7 @@ def test_install_env_with_tests_all(
 ):
     env("create", "test")
     with ev.read("test"):
-        test_dep = Spec("test-dependency").concretized()
+        test_dep = spack.concretize.concretize_one("test-dependency")
         add("depb")
         install("--test", "all")
         assert os.path.exists(test_dep.prefix)
@@ -958,7 +951,7 @@ def test_install_env_with_tests_root(
 ):
     env("create", "test")
     with ev.read("test"):
-        test_dep = Spec("test-dependency").concretized()
+        test_dep = spack.concretize.concretize_one("test-dependency")
         add("depb")
         install("--test", "root")
         assert not os.path.exists(test_dep.prefix)

lib/spack/spack/test/cmd/load.py

@@ -7,7 +7,7 @@
 
 import pytest
 
-import spack.spec
+import spack.concretize
 import spack.user_environment as uenv
 from spack.main import SpackCommand
 
@@ -49,7 +49,7 @@ def test_load_shell(shell, set_command):
         """Test that `spack load` applies prefix inspections of its required runtime deps in
         topo-order"""
         install("mpileaks")
-        mpileaks_spec = spack.spec.Spec("mpileaks").concretized()
+        mpileaks_spec = spack.concretize.concretize_one("mpileaks")
 
         # Ensure our reference variable is clean.
         os.environ["CMAKE_PREFIX_PATH"] = "/hello" + os.pathsep + "/world"
@@ -166,7 +166,7 @@ def test_unload(
     """Tests that any variables set in the user environment are undone by the
     unload command"""
     install("mpileaks")
-    mpileaks_spec = spack.spec.Spec("mpileaks").concretized()
+    mpileaks_spec = spack.concretize.concretize_one("mpileaks")
 
     # Set so unload has something to do
     os.environ["FOOBAR"] = "mpileaks"
@@ -187,7 +187,7 @@ def test_unload_fails_no_shell(
 ):
     """Test that spack unload prints an error message without a shell."""
     install("mpileaks")
-    mpileaks_spec = spack.spec.Spec("mpileaks").concretized()
+    mpileaks_spec = spack.concretize.concretize_one("mpileaks")
     os.environ[uenv.spack_loaded_hashes_var] = mpileaks_spec.dag_hash()
 
     out = unload("mpileaks", fail_on_error=False)

lib/spack/spack/test/cmd/location.py

@@ -8,9 +8,9 @@
 
 from llnl.util.filesystem import mkdirp
 
+import spack.concretize
 import spack.environment as ev
 import spack.paths
-import spack.spec
 import spack.stage
 from spack.main import SpackCommand, SpackCommandError
 
@@ -25,7 +25,7 @@
 @pytest.fixture
 def mock_spec():
     # Make it look like the source was actually expanded.
-    s = spack.spec.Spec("externaltest").concretized()
+    s = spack.concretize.concretize_one("externaltest")
     source_path = s.package.stage.source_path
     mkdirp(source_path)
     yield s, s.package

lib/spack/spack/test/cmd/logs.py

@@ -13,6 +13,7 @@
 
 import spack
 import spack.cmd.logs
+import spack.concretize
 import spack.main
 import spack.spec
 from spack.main import SpackCommand
@@ -53,7 +54,7 @@ def disable_capture(capfd):
 
 
 def test_logs_cmd_errors(install_mockery, mock_fetch, mock_archive, mock_packages):
-    spec = spack.spec.Spec("libelf").concretized()
+    spec = spack.concretize.concretize_one("libelf")
     assert not spec.installed
 
     with pytest.raises(spack.main.SpackCommandError, match="is not installed or staged"):
@@ -82,7 +83,7 @@ def test_dump_logs(install_mockery, mock_fetch, mock_archive, mock_packages, dis
     decompress them.
     """
     cmdline_spec = spack.spec.Spec("libelf")
-    concrete_spec = cmdline_spec.concretized()
+    concrete_spec = spack.concretize.concretize_one(cmdline_spec)
 
     # Sanity check, make sure this test is checking what we want: to
     # start with

lib/spack/spack/test/cmd/mirror.py

@@ -7,6 +7,7 @@
 import pytest
 
 import spack.cmd.mirror
+import spack.concretize
 import spack.config
 import spack.environment as ev
 import spack.error
@@ -60,7 +61,7 @@ def test_mirror_from_env(tmp_path, mock_packages, mock_fetch, mutable_mock_env_p
 
 @pytest.fixture
 def source_for_pkg_with_hash(mock_packages, tmpdir):
-    s = spack.spec.Spec("trivial-pkg-with-valid-hash").concretized()
+    s = spack.concretize.concretize_one("trivial-pkg-with-valid-hash")
     local_url_basename = os.path.basename(s.package.url)
     local_path = os.path.join(str(tmpdir), local_url_basename)
     with open(local_path, "w", encoding="utf-8") as f:
@@ -72,7 +73,9 @@ def source_for_pkg_with_hash(mock_packages, tmpdir):
 def test_mirror_skip_unstable(tmpdir_factory, mock_packages, config, source_for_pkg_with_hash):
     mirror_dir = str(tmpdir_factory.mktemp("mirror-dir"))
 
-    specs = [spack.spec.Spec(x).concretized() for x in ["git-test", "trivial-pkg-with-valid-hash"]]
+    specs = [
+        spack.concretize.concretize_one(x) for x in ["git-test", "trivial-pkg-with-valid-hash"]
+    ]
     spack.mirrors.utils.create(mirror_dir, specs, skip_unstable_versions=True)
 
     assert set(os.listdir(mirror_dir)) - set(["_source-cache"]) == set(
@@ -111,7 +114,7 @@ def test_exclude_specs(mock_packages, config):
 
     mirror_specs, _ = spack.cmd.mirror._specs_and_action(args)
     expected_include = set(
-        spack.spec.Spec(x).concretized() for x in ["mpich@3.0.3", "mpich@3.0.4", "mpich@3.0"]
+        spack.concretize.concretize_one(x) for x in ["mpich@3.0.3", "mpich@3.0.4", "mpich@3.0"]
     )
     expected_exclude = set(spack.spec.Spec(x) for x in ["mpich@3.0.1", "mpich@3.0.2", "mpich@1.0"])
     assert expected_include <= set(mirror_specs)
@@ -145,7 +148,7 @@ def test_exclude_file(mock_packages, tmpdir, config):
 
     mirror_specs, _ = spack.cmd.mirror._specs_and_action(args)
     expected_include = set(
-        spack.spec.Spec(x).concretized() for x in ["mpich@3.0.3", "mpich@3.0.4", "mpich@3.0"]
+        spack.concretize.concretize_one(x) for x in ["mpich@3.0.3", "mpich@3.0.4", "mpich@3.0"]
     )
     expected_exclude = set(spack.spec.Spec(x) for x in ["mpich@3.0.1", "mpich@3.0.2", "mpich@1.0"])
     assert expected_include <= set(mirror_specs)

lib/spack/spack/test/cmd/module.py

@@ -7,12 +7,12 @@
 
 import pytest
 
+import spack.concretize
 import spack.config
 import spack.main
 import spack.modules
 import spack.modules.lmod
 import spack.repo
-import spack.spec
 import spack.store
 from spack.installer import PackageInstaller
 
@@ -33,7 +33,7 @@ def ensure_module_files_are_there(mock_repo_path, mock_store, mock_configuration
 
 
 def _module_files(module_type, *specs):
-    specs = [spack.spec.Spec(x).concretized() for x in specs]
+    specs = [spack.concretize.concretize_one(x) for x in specs]
     writer_cls = spack.modules.module_types[module_type]
     return [writer_cls(spec, "default").layout.filename for spec in specs]
 
@@ -184,12 +184,15 @@ def test_setdefault_command(mutable_database, mutable_config):
     # Install two different versions of pkg-a
     other_spec, preferred = "pkg-a@1.0", "pkg-a@2.0"
 
-    specs = [spack.spec.Spec(other_spec).concretized(), spack.spec.Spec(preferred).concretized()]
+    specs = [
+        spack.concretize.concretize_one(other_spec),
+        spack.concretize.concretize_one(preferred),
+    ]
     PackageInstaller([s.package for s in specs], explicit=True, fake=True).install()
 
     writers = {
-        preferred: writer_cls(spack.spec.Spec(preferred).concretized(), "default"),
+        preferred: writer_cls(specs[1], "default"),
-        other_spec: writer_cls(spack.spec.Spec(other_spec).concretized(), "default"),
+        other_spec: writer_cls(specs[0], "default"),
     }
 
     # Create two module files for the same software

lib/spack/spack/test/cmd/tags.py

@@ -2,9 +2,9 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+import spack.concretize
 import spack.main
 import spack.repo
-import spack.spec
 from spack.installer import PackageInstaller
 
 tags = spack.main.SpackCommand("tags")
@@ -47,7 +47,7 @@ class tag_path:
 
 
 def test_tags_installed(install_mockery, mock_fetch):
-    s = spack.spec.Spec("mpich").concretized()
+    s = spack.concretize.concretize_one("mpich")
     PackageInstaller([s.package], explicit=True, fake=True).install()
 
     out = tags("-i")

lib/spack/spack/test/cmd/test.py

@@ -11,10 +11,10 @@
 
 import spack.cmd.common.arguments
 import spack.cmd.test
+import spack.concretize
 import spack.config
 import spack.install_test
 import spack.paths
-import spack.spec
 from spack.install_test import TestStatus
 from spack.main import SpackCommand
 
@@ -240,7 +240,7 @@ def test_read_old_results(mock_packages, mock_test_stage):
 
 def test_test_results_none(mock_packages, mock_test_stage):
     name = "trivial"
-    spec = spack.spec.Spec("trivial-smoke-test").concretized()
+    spec = spack.concretize.concretize_one("trivial-smoke-test")
     suite = spack.install_test.TestSuite([spec], name)
     suite.ensure_stage()
     spack.install_test.write_test_suite_file(suite)
@@ -255,7 +255,7 @@ def test_test_results_none(mock_packages, mock_test_stage):
 def test_test_results_status(mock_packages, mock_test_stage, status):
     """Confirm 'spack test results' returns expected status."""
     name = "trivial"
-    spec = spack.spec.Spec("trivial-smoke-test").concretized()
+    spec = spack.concretize.concretize_one("trivial-smoke-test")
     suite = spack.install_test.TestSuite([spec], name)
     suite.ensure_stage()
     spack.install_test.write_test_suite_file(suite)
@@ -278,7 +278,7 @@ def test_test_results_status(mock_packages, mock_test_stage, status):
 def test_report_filename_for_cdash(install_mockery, mock_fetch):
     """Test that the temporary file used to write Testing.xml for CDash is not the upload URL"""
     name = "trivial"
-    spec = spack.spec.Spec("trivial-smoke-test").concretized()
+    spec = spack.concretize.concretize_one("trivial-smoke-test")
     suite = spack.install_test.TestSuite([spec], name)
     suite.ensure_stage()
 

lib/spack/spack/test/cmd/undevelop.py

@@ -1,8 +1,8 @@
 # Copyright Spack Project Developers. See COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
+import spack.concretize
 import spack.environment as ev
-import spack.spec
 from spack.main import SpackCommand
 
 undevelop = SpackCommand("undevelop")
@@ -30,9 +30,9 @@ def test_undevelop(tmpdir, mutable_config, mock_packages, mutable_mock_env_path)
 
         env("create", "test", "./spack.yaml")
         with ev.read("test"):
-            before = spack.spec.Spec("mpich").concretized()
+            before = spack.concretize.concretize_one("mpich")
             undevelop("mpich")
-            after = spack.spec.Spec("mpich").concretized()
+            after = spack.concretize.concretize_one("mpich")
 
     # Removing dev spec from environment changes concretization
     assert before.satisfies("dev_path=*")

lib/spack/spack/test/cmd/verify.py

@@ -7,7 +7,7 @@
 
 import llnl.util.filesystem as fs
 
-import spack.spec
+import spack.concretize
 import spack.store
 import spack.util.spack_json as sjson
 import spack.verify
@@ -65,7 +65,7 @@ def test_single_file_verify_cmd(tmpdir):
 def test_single_spec_verify_cmd(tmpdir, mock_packages, mock_archive, mock_fetch, install_mockery):
     # Test the verify command interface to verify a single spec
     install("libelf")
-    s = spack.spec.Spec("libelf").concretized()
+    s = spack.concretize.concretize_one("libelf")
     prefix = s.prefix
     hash = s.dag_hash()
 

lib/spack/spack/test/cmd/view.py

@@ -9,10 +9,10 @@
 
 from llnl.util.symlink import _windows_can_symlink
 
+import spack.concretize
 import spack.util.spack_yaml as s_yaml
 from spack.installer import PackageInstaller
 from spack.main import SpackCommand
-from spack.spec import Spec
 
 extensions = SpackCommand("extensions")
 install = SpackCommand("install")
@@ -190,7 +190,7 @@ def test_view_fails_with_missing_projections_file(tmpdir):
 def test_view_files_not_ignored(
     tmpdir, mock_packages, mock_archive, mock_fetch, install_mockery, cmd, with_projection
 ):
-    spec = Spec("view-not-ignored").concretized()
+    spec = spack.concretize.concretize_one("view-not-ignored")
     pkg = spec.package
     PackageInstaller([pkg], explicit=True).install()
     pkg.assert_installed(spec.prefix)

lib/spack/spack/test/concretization/compiler_runtimes.py

@@ -8,6 +8,7 @@
 
 import archspec.cpu
 
+import spack.concretize
 import spack.config
 import spack.paths
 import spack.repo
@@ -20,7 +21,7 @@
 
 
 def _concretize_with_reuse(*, root_str, reused_str):
-    reused_spec = spack.spec.Spec(reused_str).concretized()
+    reused_spec = spack.concretize.concretize_one(reused_str)
     setup = spack.solver.asp.SpackSolverSetup(tests=False)
     driver = spack.solver.asp.PyclingoDriver()
     result, _, _ = driver.solve(setup, [spack.spec.Spec(f"{root_str}")], reuse=[reused_spec])
@@ -44,7 +45,7 @@ def enable_runtimes():
 
 
 def test_correct_gcc_runtime_is_injected_as_dependency(runtime_repo):
-    s = spack.spec.Spec("pkg-a%gcc@10.2.1 ^pkg-b%gcc@9.4.0").concretized()
+    s = spack.concretize.concretize_one("pkg-a%gcc@10.2.1 ^pkg-b%gcc@9.4.0")
     a, b = s["pkg-a"], s["pkg-b"]
 
     # Both a and b should depend on the same gcc-runtime directly
@@ -61,7 +62,7 @@ def test_external_nodes_do_not_have_runtimes(runtime_repo, mutable_config, tmp_p
     packages_yaml = {"pkg-b": {"externals": [{"spec": "pkg-b@1.0", "prefix": f"{str(tmp_path)}"}]}}
     spack.config.set("packages", packages_yaml)
 
-    s = spack.spec.Spec("pkg-a%gcc@10.2.1").concretized()
+    s = spack.concretize.concretize_one("pkg-a%gcc@10.2.1")
 
     a, b = s["pkg-a"], s["pkg-b"]
 

lib/spack/spack/test/concretization/errors.py

@@ -4,9 +4,9 @@
 
 import pytest
 
+import spack.concretize
 import spack.config
 import spack.solver.asp
-import spack.spec
 
 version_error_messages = [
     "Cannot satisfy 'fftw@:1.0' and 'fftw@1.1:",
@@ -57,7 +57,7 @@ def test_error_messages(error_messages, config_set, spec, mock_packages, mutable
         spack.config.set(path, conf)
 
     with pytest.raises(spack.solver.asp.UnsatisfiableSpecError) as e:
-        _ = spack.spec.Spec(spec).concretized()
+        _ = spack.concretize.concretize_one(spec)
 
     for em in error_messages:
         assert em in str(e.value)

lib/spack/spack/test/concretization/flag_mixing.py

@@ -11,7 +11,6 @@
 import spack.paths
 import spack.repo
 import spack.util.spack_yaml as syaml
-from spack.spec import Spec
 
 """
 These tests include the following package DAGs:
@@ -63,12 +62,12 @@ def test_mix_spec_and_requirements(concretize_scope, test_repo):
 """
     update_concretize_scope(conf_str, "packages")
 
-    s1 = Spec('y cflags="-a"').concretized()
+    s1 = spack.concretize.concretize_one('y cflags="-a"')
     assert s1.satisfies('cflags="-a -c"')
 
 
 def test_mix_spec_and_dependent(concretize_scope, test_repo):
-    s1 = Spec('x ^y cflags="-a"').concretized()
+    s1 = spack.concretize.concretize_one('x ^y cflags="-a"')
     assert s1["y"].satisfies('cflags="-a -d1"')
 
 
@@ -93,7 +92,7 @@ def test_mix_spec_and_compiler_cfg(concretize_scope, test_repo):
     conf_str = _compiler_cfg_one_entry_with_cflags("-Wall")
     update_concretize_scope(conf_str, "compilers")
 
-    s1 = Spec('y %gcc@12.100.100 cflags="-O2"').concretized()
+    s1 = spack.concretize.concretize_one('y %gcc@12.100.100 cflags="-O2"')
     assert s1.satisfies('cflags="-Wall -O2"')
 
 
@@ -160,7 +159,7 @@ def test_flag_order_and_grouping(
     if cmd_flags:
         spec_str += f' cflags="{cmd_flags}"'
 
-    root_spec = Spec(spec_str).concretized()
+    root_spec = spack.concretize.concretize_one(spec_str)
     spec = root_spec["y"]
     satisfy_flags = " ".join(x for x in [cmd_flags, req_flags, cmp_flags, expected_dflags] if x)
     assert spec.satisfies(f'cflags="{satisfy_flags}"')
@@ -168,11 +167,11 @@ def test_flag_order_and_grouping(
 
 
 def test_two_dependents_flag_mixing(concretize_scope, test_repo):
-    root_spec1 = Spec("w~moveflaglater").concretized()
+    root_spec1 = spack.concretize.concretize_one("w~moveflaglater")
     spec1 = root_spec1["y"]
     assert spec1.compiler_flags["cflags"] == "-d0 -d1 -d2".split()
 
-    root_spec2 = Spec("w+moveflaglater").concretized()
+    root_spec2 = spack.concretize.concretize_one("w+moveflaglater")
     spec2 = root_spec2["y"]
     assert spec2.compiler_flags["cflags"] == "-d3 -d1 -d2".split()
 
@@ -181,7 +180,7 @@ def test_propagate_and_compiler_cfg(concretize_scope, test_repo):
     conf_str = _compiler_cfg_one_entry_with_cflags("-f2")
     update_concretize_scope(conf_str, "compilers")
 
-    root_spec = Spec("v %gcc@12.100.100 cflags=='-f1'").concretized()
+    root_spec = spack.concretize.concretize_one("v %gcc@12.100.100 cflags=='-f1'")
     assert root_spec["y"].satisfies("cflags='-f1 -f2'")
 
 
@@ -190,7 +189,7 @@ def test_propagate_and_compiler_cfg(concretize_scope, test_repo):
 
 
 def test_propagate_and_pkg_dep(concretize_scope, test_repo):
-    root_spec1 = Spec("x ~activatemultiflag cflags=='-f1'").concretized()
+    root_spec1 = spack.concretize.concretize_one("x ~activatemultiflag cflags=='-f1'")
     assert root_spec1["y"].satisfies("cflags='-f1 -d1'")
 
 
@@ -202,7 +201,7 @@ def test_propagate_and_require(concretize_scope, test_repo):
 """
     update_concretize_scope(conf_str, "packages")
 
-    root_spec1 = Spec("v cflags=='-f1'").concretized()
+    root_spec1 = spack.concretize.concretize_one("v cflags=='-f1'")
     assert root_spec1["y"].satisfies("cflags='-f1 -f2'")
 
     # Next, check that a requirement does not "undo" a request for
@@ -214,7 +213,7 @@ def test_propagate_and_require(concretize_scope, test_repo):
 """
     update_concretize_scope(conf_str, "packages")
 
-    root_spec2 = Spec("v cflags=='-f1'").concretized()
+    root_spec2 = spack.concretize.concretize_one("v cflags=='-f1'")
     assert root_spec2["y"].satisfies("cflags='-f1'")
 
     # Note: requirements cannot enforce propagation: any attempt to do
@@ -258,7 +257,7 @@ def test_diamond_dep_flag_mixing(concretize_scope, test_repo):
     nodes of the diamond always appear in the same order).
     `Spec.traverse` is responsible for handling both of these needs.
     """
-    root_spec1 = Spec("t").concretized()
+    root_spec1 = spack.concretize.concretize_one("t")
     spec1 = root_spec1["y"]
     assert spec1.satisfies('cflags="-c1 -c2 -d1 -d2 -e1 -e2"')
     assert spec1.compiler_flags["cflags"] == "-c1 -c2 -e1 -e2 -d1 -d2".split()

lib/spack/spack/test/concretization/preferences.py

@@ -7,6 +7,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.config
 import spack.package_prefs
 import spack.repo
@@ -46,7 +47,7 @@ def configure_permissions():
 
 
 def concretize(abstract_spec):
-    return Spec(abstract_spec).concretized()
+    return spack.concretize.concretize_one(abstract_spec)
 
 
 def update_packages(pkgname, section, value):
@@ -111,7 +112,7 @@ def test_preferred_variants_from_wildcard(self):
     def test_preferred_compilers(self, compiler_str, spec_str):
         """Test preferred compilers are applied correctly"""
         update_packages("all", "compiler", [compiler_str])
-        spec = spack.spec.Spec(spec_str).concretized()
+        spec = spack.concretize.concretize_one(spec_str)
         assert spec.compiler == CompilerSpec(compiler_str)
 
     def test_preferred_target(self, mutable_mock_repo):
@@ -213,15 +214,13 @@ def test_config_set_pkg_property_new(self, mock_repo_path):
 
     def test_preferred(self):
         """ "Test packages with some version marked as preferred=True"""
-        spec = Spec("python")
+        spec = spack.concretize.concretize_one("python")
-        spec.concretize()
         assert spec.version == Version("2.7.11")
 
         # now add packages.yaml with versions other than preferred
         # ensure that once config is in place, non-preferred version is used
         update_packages("python", "version", ["3.5.0"])
-        spec = Spec("python")
+        spec = spack.concretize.concretize_one("python")
-        spec.concretize()
         assert spec.version == Version("3.5.0")
 
     def test_preferred_undefined_raises(self):
@@ -229,7 +228,7 @@ def test_preferred_undefined_raises(self):
         update_packages("python", "version", ["3.5.0.1"])
         spec = Spec("python")
         with pytest.raises(ConfigError):
-            spec.concretize()
+            spack.concretize.concretize_one(spec)
 
     def test_preferred_truncated(self):
         """Versions without "=" are treated as version ranges: if there is
@@ -237,35 +236,29 @@ def test_preferred_truncated(self):
         (don't define a new version).
         """
         update_packages("python", "version", ["3.5"])
-        spec = Spec("python")
+        spec = spack.concretize.concretize_one("python")
-        spec.concretize()
         assert spec.satisfies("@3.5.1")
 
     def test_develop(self):
         """Test concretization with develop-like versions"""
-        spec = Spec("develop-test")
+        spec = spack.concretize.concretize_one("develop-test")
-        spec.concretize()
         assert spec.version == Version("0.2.15")
-        spec = Spec("develop-test2")
+        spec = spack.concretize.concretize_one("develop-test2")
-        spec.concretize()
         assert spec.version == Version("0.2.15")
 
         # now add packages.yaml with develop-like versions
         # ensure that once config is in place, develop-like version is used
         update_packages("develop-test", "version", ["develop"])
-        spec = Spec("develop-test")
+        spec = spack.concretize.concretize_one("develop-test")
-        spec.concretize()
         assert spec.version == Version("develop")
 
         update_packages("develop-test2", "version", ["0.2.15.develop"])
-        spec = Spec("develop-test2")
+        spec = spack.concretize.concretize_one("develop-test2")
-        spec.concretize()
         assert spec.version == Version("0.2.15.develop")
 
     def test_external_mpi(self):
         # make sure this doesn't give us an external first.
-        spec = Spec("mpi")
+        spec = spack.concretize.concretize_one("mpi")
-        spec.concretize()
         assert not spec["mpi"].external
 
         # load config
@@ -284,8 +277,7 @@ def test_external_mpi(self):
         spack.config.set("packages", conf, scope="concretize")
 
         # ensure that once config is in place, external is used
-        spec = Spec("mpi")
+        spec = spack.concretize.concretize_one("mpi")
-        spec.concretize()
         assert spec["mpich"].external_path == os.path.sep + os.path.join("dummy", "path")
 
     def test_external_module(self, monkeypatch):
@@ -300,8 +292,7 @@ def mock_module(cmd, module):
 
         monkeypatch.setattr(spack.util.module_cmd, "module", mock_module)
 
-        spec = Spec("mpi")
+        spec = spack.concretize.concretize_one("mpi")
-        spec.concretize()
         assert not spec["mpi"].external
 
         # load config
@@ -320,8 +311,7 @@ def mock_module(cmd, module):
         spack.config.set("packages", conf, scope="concretize")
 
         # ensure that once config is in place, external is used
-        spec = Spec("mpi")
+        spec = spack.concretize.concretize_one("mpi")
-        spec.concretize()
         assert spec["mpich"].external_path == os.path.sep + os.path.join("dummy", "path")
 
     def test_buildable_false(self):
@@ -467,7 +457,7 @@ def test_variant_not_flipped_to_pull_externals(self):
         """Test that a package doesn't prefer pulling in an
         external to using the default value of a variant.
         """
-        s = Spec("vdefault-or-external-root").concretized()
+        s = spack.concretize.concretize_one("vdefault-or-external-root")
 
         assert "~external" in s["vdefault-or-external"]
         assert "externaltool" not in s
@@ -479,7 +469,7 @@ def test_dependencies_cant_make_version_parent_score_better(self):
         that makes the overall version score even or better and maybe
         has a better score in some lower priority criteria.
         """
-        s = Spec("version-test-root").concretized()
+        s = spack.concretize.concretize_one("version-test-root")
 
         assert s.satisfies("^version-test-pkg@2.4.6")
         assert "version-test-dependency-preferred" not in s
@@ -497,13 +487,13 @@ def test_multivalued_variants_are_lower_priority_than_providers(self):
         with spack.config.override(
             "packages:all", {"providers": {"somevirtual": ["some-virtual-preferred"]}}
         ):
-            s = Spec("somevirtual").concretized()
+            s = spack.concretize.concretize_one("somevirtual")
             assert s.name == "some-virtual-preferred"
 
     @pytest.mark.regression("26721,19736")
     def test_sticky_variant_accounts_for_packages_yaml(self):
         with spack.config.override("packages:sticky-variant", {"variants": "+allow-gcc"}):
-            s = Spec("sticky-variant %gcc").concretized()
+            s = spack.concretize.concretize_one("sticky-variant %gcc")
             assert s.satisfies("%gcc") and s.satisfies("+allow-gcc")
 
     @pytest.mark.regression("41134")
@@ -512,5 +502,5 @@ def test_default_preference_variant_different_type_does_not_error(self):
         packages.yaml doesn't fail with an error.
         """
         with spack.config.override("packages:all", {"variants": "+foo"}):
-            s = Spec("pkg-a").concretized()
+            s = spack.concretize.concretize_one("pkg-a")
             assert s.satisfies("foo=bar")

lib/spack/spack/test/concretization/requirements.py

@@ -6,6 +6,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.config
 import spack.error
 import spack.package_base
@@ -42,7 +43,7 @@ def test_one_package_multiple_reqs(concretize_scope, test_repo):
     - "~shared"
 """
     update_packages_config(conf_str)
-    y_spec = Spec("y").concretized()
+    y_spec = spack.concretize.concretize_one("y")
     assert y_spec.satisfies("@2.4~shared")
 
 
@@ -57,7 +58,7 @@ def test_requirement_isnt_optional(concretize_scope, test_repo):
 """
     update_packages_config(conf_str)
     with pytest.raises(UnsatisfiableSpecError):
-        Spec("x@1.1").concretize()
+        spack.concretize.concretize_one("x@1.1")
 
 
 def test_require_undefined_version(concretize_scope, test_repo):
@@ -74,7 +75,7 @@ def test_require_undefined_version(concretize_scope, test_repo):
 """
     update_packages_config(conf_str)
     with pytest.raises(spack.error.ConfigError):
-        Spec("x").concretize()
+        spack.concretize.concretize_one("x")
 
 
 def test_require_truncated(concretize_scope, test_repo):
@@ -89,7 +90,7 @@ def test_require_truncated(concretize_scope, test_repo):
     require: "@1"
 """
     update_packages_config(conf_str)
-    xspec = Spec("x").concretized()
+    xspec = spack.concretize.concretize_one("x")
     assert xspec.satisfies("@1.1")
 
 
@@ -159,7 +160,7 @@ def test_requirement_adds_new_version(
     )
     update_packages_config(conf_str)
 
-    s1 = Spec("v").concretized()
+    s1 = spack.concretize.concretize_one("v")
     assert s1.satisfies("@2.2")
     # Make sure the git commit info is retained
     assert isinstance(s1.version, spack.version.GitVersion)
@@ -180,7 +181,7 @@ def test_requirement_adds_version_satisfies(
     )
 
     # Sanity check: early version of T does not include U
-    s0 = Spec("t@2.0").concretized()
+    s0 = spack.concretize.concretize_one("t@2.0")
     assert not ("u" in s0)
 
     conf_str = """\
@@ -192,7 +193,7 @@ def test_requirement_adds_version_satisfies(
     )
     update_packages_config(conf_str)
 
-    s1 = Spec("t").concretized()
+    s1 = spack.concretize.concretize_one("t")
     assert "u" in s1
     assert s1.satisfies("@2.2")
 
@@ -218,7 +219,7 @@ def test_requirement_adds_git_hash_version(
 """
     update_packages_config(conf_str)
 
-    s1 = Spec("v").concretized()
+    s1 = spack.concretize.concretize_one("v")
     assert isinstance(s1.version, spack.version.GitVersion)
     assert s1.satisfies(f"v@{a_commit_hash}")
 
@@ -239,8 +240,8 @@ def test_requirement_adds_multiple_new_versions(
 """
     update_packages_config(conf_str)
 
-    assert Spec("v").concretized().satisfies(f"@{commits[0]}=2.2")
+    assert spack.concretize.concretize_one("v").satisfies(f"@{commits[0]}=2.2")
-    assert Spec("v@2.3").concretized().satisfies(f"v@{commits[1]}=2.3")
+    assert spack.concretize.concretize_one("v@2.3").satisfies(f"v@{commits[1]}=2.3")
 
 
 # TODO: this belongs in the concretize_preferences test module but uses
@@ -263,11 +264,11 @@ def test_preference_adds_new_version(
 """
     update_packages_config(conf_str)
 
-    assert Spec("v").concretized().satisfies(f"@{commits[0]}=2.2")
+    assert spack.concretize.concretize_one("v").satisfies(f"@{commits[0]}=2.2")
-    assert Spec("v@2.3").concretized().satisfies(f"@{commits[1]}=2.3")
+    assert spack.concretize.concretize_one("v@2.3").satisfies(f"@{commits[1]}=2.3")
 
     # When installing by hash, a lookup is triggered, so it's not mapped to =2.3.
-    s3 = Spec(f"v@{commits[1]}").concretized()
+    s3 = spack.concretize.concretize_one(f"v@{commits[1]}")
     assert s3.satisfies(f"v@{commits[1]}")
     assert not s3.satisfies("@2.3")
 
@@ -287,7 +288,7 @@ def test_external_adds_new_version_that_is_preferred(concretize_scope, test_repo
 """
     update_packages_config(conf_str)
 
-    spec = Spec("x").concretized()
+    spec = spack.concretize.concretize_one("x")
     assert spec["y"].satisfies("@2.7")
     assert spack.version.Version("2.7") not in spec["y"].package.versions
 
@@ -296,7 +297,7 @@ def test_requirement_is_successfully_applied(concretize_scope, test_repo):
     """If a simple requirement can be satisfied, make sure the
     concretization succeeds and the requirement spec is applied.
     """
-    s1 = Spec("x").concretized()
+    s1 = spack.concretize.concretize_one("x")
     # Without any requirements/preferences, the later version is preferred
     assert s1.satisfies("@1.1")
 
@@ -306,7 +307,7 @@ def test_requirement_is_successfully_applied(concretize_scope, test_repo):
     require: "@1.0"
 """
     update_packages_config(conf_str)
-    s2 = Spec("x").concretized()
+    s2 = spack.concretize.concretize_one("x")
     # The requirement forces choosing the eariler version
     assert s2.satisfies("@1.0")
 
@@ -323,7 +324,7 @@ def test_multiple_packages_requirements_are_respected(concretize_scope, test_rep
     require: "@2.4"
 """
     update_packages_config(conf_str)
-    spec = Spec("x").concretized()
+    spec = spack.concretize.concretize_one("x")
     assert spec["x"].satisfies("@1.0")
     assert spec["y"].satisfies("@2.4")
 
@@ -339,7 +340,7 @@ def test_oneof(concretize_scope, test_repo):
     - one_of: ["@2.4", "~shared"]
 """
     update_packages_config(conf_str)
-    spec = Spec("x").concretized()
+    spec = spack.concretize.concretize_one("x")
     # The concretizer only has to satisfy one of @2.4/~shared, and @2.4
     # comes first so it is prioritized
     assert spec["y"].satisfies("@2.4+shared")
@@ -358,10 +359,10 @@ def test_one_package_multiple_oneof_groups(concretize_scope, test_repo):
 """
     update_packages_config(conf_str)
 
-    s1 = Spec("y@2.5").concretized()
+    s1 = spack.concretize.concretize_one("y@2.5")
     assert s1.satisfies("%clang~shared")
 
-    s2 = Spec("y@2.4").concretized()
+    s2 = spack.concretize.concretize_one("y@2.4")
     assert s2.satisfies("%gcc+shared")
 
 
@@ -377,10 +378,10 @@ def test_require_cflags(concretize_scope, mock_packages):
 """
     update_packages_config(conf_str)
 
-    spec_mpich2 = Spec("mpich2").concretized()
+    spec_mpich2 = spack.concretize.concretize_one("mpich2")
     assert spec_mpich2.satisfies("cflags=-g")
 
-    spec_mpi = Spec("mpi").concretized()
+    spec_mpi = spack.concretize.concretize_one("mpi")
     assert spec_mpi.satisfies("mpich cflags=-O1")
 
 
@@ -403,7 +404,7 @@ def test_requirements_for_package_that_is_not_needed(concretize_scope, test_repo
 """
     update_packages_config(conf_str)
 
-    s1 = Spec("v").concretized()
+    s1 = spack.concretize.concretize_one("v")
     assert s1.satisfies("@2.1")
 
 
@@ -420,10 +421,10 @@ def test_oneof_ordering(concretize_scope, test_repo):
 """
     update_packages_config(conf_str)
 
-    s1 = Spec("y").concretized()
+    s1 = spack.concretize.concretize_one("y")
     assert s1.satisfies("@2.4")
 
-    s2 = Spec("y@2.5").concretized()
+    s2 = spack.concretize.concretize_one("y@2.5")
     assert s2.satisfies("@2.5")
 
 
@@ -437,14 +438,14 @@ def test_reuse_oneof(concretize_scope, test_repo, tmp_path, mock_fetch):
 
     store_dir = tmp_path / "store"
     with spack.store.use_store(str(store_dir)):
-        s1 = Spec("y@2.5 ~shared").concretized()
+        s1 = spack.concretize.concretize_one("y@2.5~shared")
         PackageInstaller([s1.package], fake=True, explicit=True).install()
 
         update_packages_config(conf_str)
 
         with spack.config.override("concretizer:reuse", True):
-            s2 = Spec("y").concretized()
+            s2 = spack.concretize.concretize_one("y")
-            assert not s2.satisfies("@2.5 ~shared")
+            assert not s2.satisfies("@2.5~shared")
 
 
 @pytest.mark.parametrize(
@@ -472,7 +473,7 @@ def test_requirements_and_deprecated_versions(
     update_packages_config(conf_str)
 
     with spack.config.override("config:deprecated", allow_deprecated):
-        s1 = Spec("y").concretized()
+        s1 = spack.concretize.concretize_one("y")
         for constrain in expected:
             assert s1.satisfies(constrain)
 
@@ -490,7 +491,7 @@ def test_default_requirements_with_all(spec_str, requirement_str, concretize_sco
 """
     update_packages_config(conf_str)
 
-    spec = Spec(spec_str).concretized()
+    spec = spack.concretize.concretize_one(spec_str)
     for s in spec.traverse():
         assert s.satisfies(requirement_str)
 
@@ -499,7 +500,7 @@ def test_default_requirements_with_all(spec_str, requirement_str, concretize_sco
     "requirements,expectations",
     [
         (("%gcc", "%clang"), ("%gcc", "%clang")),
-        (("%gcc ~shared", "@1.0"), ("%gcc ~shared", "@1.0 +shared")),
+        (("%gcc~shared", "@1.0"), ("%gcc~shared", "@1.0+shared")),
     ],
 )
 def test_default_and_package_specific_requirements(
@@ -517,7 +518,7 @@ def test_default_and_package_specific_requirements(
 """
     update_packages_config(conf_str)
 
-    spec = Spec("x").concretized()
+    spec = spack.concretize.concretize_one("x")
     assert spec.satisfies(specific_exp)
     for s in spec.traverse(root=False):
         assert s.satisfies(generic_exp)
@@ -532,7 +533,7 @@ def test_requirements_on_virtual(mpi_requirement, concretize_scope, mock_package
 """
     update_packages_config(conf_str)
 
-    spec = Spec("callpath").concretized()
+    spec = spack.concretize.concretize_one("callpath")
     assert "mpi" in spec
     assert mpi_requirement in spec
 
@@ -553,7 +554,7 @@ def test_requirements_on_virtual_and_on_package(
 """
     update_packages_config(conf_str)
 
-    spec = Spec("callpath").concretized()
+    spec = spack.concretize.concretize_one("callpath")
     assert "mpi" in spec
     assert mpi_requirement in spec
     assert spec["mpi"].satisfies(specific_requirement)
@@ -567,10 +568,10 @@ def test_incompatible_virtual_requirements_raise(concretize_scope, mock_packages
     """
     update_packages_config(conf_str)
 
-    spec = Spec("callpath ^zmpi")
+    spec = Spec("callpath^zmpi")
     # TODO (multiple nodes): recover a better error message later
     with pytest.raises((UnsatisfiableSpecError, InternalConcretizerError)):
-        spec.concretize()
+        spack.concretize.concretize_one(spec)
 
 
 def test_non_existing_variants_under_all(concretize_scope, mock_packages):
@@ -582,7 +583,7 @@ def test_non_existing_variants_under_all(concretize_scope, mock_packages):
     """
     update_packages_config(conf_str)
 
-    spec = Spec("callpath ^zmpi").concretized()
+    spec = spack.concretize.concretize_one("callpath^zmpi")
     assert "~foo" not in spec
 
 
@@ -657,7 +658,7 @@ def test_conditional_requirements_from_packages_yaml(
     and optional when the condition is not met.
     """
     update_packages_config(packages_yaml)
-    spec = Spec(spec_str).concretized()
+    spec = spack.concretize.concretize_one(spec_str)
     for match_str, expected in expected_satisfies:
         assert spec.satisfies(match_str) is expected
 
@@ -733,7 +734,7 @@ def test_requirements_fail_with_custom_message(
     """
     update_packages_config(packages_yaml)
     with pytest.raises(spack.error.SpackError, match=expected_message):
-        Spec(spec_str).concretized()
+        spack.concretize.concretize_one(spec_str)
 
 
 def test_skip_requirement_when_default_requirement_condition_cannot_be_met(
@@ -752,9 +753,9 @@ def test_skip_requirement_when_default_requirement_condition_cannot_be_met(
               when: "+shared"
     """
     update_packages_config(packages_yaml)
-    s = Spec("mpileaks").concretized()
+    s = spack.concretize.concretize_one("mpileaks")
 
-    assert s.satisfies("%clang +shared")
+    assert s.satisfies("%clang+shared")
     # Sanity checks that 'callpath' doesn't have the shared variant, but that didn't
     # cause failures during concretization.
     assert "shared" not in s["callpath"].variants
@@ -781,12 +782,12 @@ def test_requires_directive(concretize_scope, mock_packages):
     spack.config.CONFIG.clear_caches()
 
     # This package requires either clang or gcc
-    s = Spec("requires_clang_or_gcc").concretized()
+    s = spack.concretize.concretize_one("requires_clang_or_gcc")
     assert s.satisfies("%gcc@12.0.0")
 
     # This package can only be compiled with clang
     with pytest.raises(spack.error.SpackError, match="can only be compiled with Clang"):
-        Spec("requires_clang").concretized()
+        spack.concretize.concretize_one("requires_clang")
 
 
 @pytest.mark.parametrize(
@@ -839,20 +840,20 @@ def test_default_requirements_semantic(packages_yaml, concretize_scope, mock_pac
     """
     update_packages_config(packages_yaml)
 
-    # Regular zlib concretize to +shared
+    # Regular zlib concretize to+shared
-    s = Spec("zlib").concretized()
+    s = spack.concretize.concretize_one("zlib")
     assert s.satisfies("+shared")
 
     # If we specify the variant we can concretize only the one matching the constraint
-    s = Spec("zlib +shared").concretized()
+    s = spack.concretize.concretize_one("zlib+shared")
     assert s.satisfies("+shared")
     with pytest.raises(UnsatisfiableSpecError):
-        Spec("zlib ~shared").concretized()
+        spack.concretize.concretize_one("zlib~shared")
 
     # A spec without the shared variant still concretize
-    s = Spec("pkg-a").concretized()
+    s = spack.concretize.concretize_one("pkg-a")
-    assert not s.satisfies("pkg-a +shared")
+    assert not s.satisfies("pkg-a+shared")
-    assert not s.satisfies("pkg-a ~shared")
+    assert not s.satisfies("pkg-a~shared")
 
 
 @pytest.mark.parametrize(
@@ -896,7 +897,7 @@ def test_default_requirements_semantic(packages_yaml, concretize_scope, mock_pac
             """
         packages:
           all:
-            require: "libs=static +feefoo"
+            require: "libs=static+feefoo"
     """,
             "multivalue-variant",
             ["libs=shared"],
@@ -911,7 +912,7 @@ def test_default_requirements_semantic_with_mv_variants(
     from MV variants.
     """
     update_packages_config(packages_yaml)
-    s = Spec(spec_str).concretized()
+    s = spack.concretize.concretize_one(spec_str)
 
     for constraint in expected:
         assert s.satisfies(constraint), constraint
@@ -936,7 +937,7 @@ def test_requiring_package_on_multiple_virtuals(concretize_scope, mock_packages)
         require: intel-parallel-studio
     """
     )
-    s = Spec("dla-future").concretized()
+    s = spack.concretize.concretize_one("dla-future")
 
     assert s["blas"].name == "intel-parallel-studio"
     assert s["lapack"].name == "intel-parallel-studio"
@@ -989,7 +990,7 @@ def test_strong_preferences_packages_yaml(
 ):
     """Tests that "preferred" specs are stronger than usual preferences, but can be overridden."""
     update_packages_config(packages_yaml)
-    s = Spec(spec_str).concretized()
+    s = spack.concretize.concretize_one(spec_str)
 
     for constraint in expected:
         assert s.satisfies(constraint), constraint
@@ -1038,29 +1039,29 @@ def test_conflict_packages_yaml(packages_yaml, spec_str, concretize_scope, mock_
     """Tests conflicts that are specified from configuration files."""
     update_packages_config(packages_yaml)
     with pytest.raises(UnsatisfiableSpecError):
-        Spec(spec_str).concretized()
+        spack.concretize.concretize_one(spec_str)
 
 
 @pytest.mark.parametrize(
     "spec_str,expected,not_expected",
     [
         (
-            "forward-multi-value +cuda cuda_arch=10 ^dependency-mv~cuda",
+            "forward-multi-value+cuda cuda_arch=10^dependency-mv~cuda",
             ["cuda_arch=10", "^dependency-mv~cuda"],
             ["cuda_arch=11", "^dependency-mv cuda_arch=10", "^dependency-mv cuda_arch=11"],
         ),
         (
-            "forward-multi-value +cuda cuda_arch=10 ^dependency-mv+cuda",
+            "forward-multi-value+cuda cuda_arch=10^dependency-mv+cuda",
             ["cuda_arch=10", "^dependency-mv cuda_arch=10"],
             ["cuda_arch=11", "^dependency-mv cuda_arch=11"],
         ),
         (
-            "forward-multi-value +cuda cuda_arch=11 ^dependency-mv+cuda",
+            "forward-multi-value+cuda cuda_arch=11^dependency-mv+cuda",
             ["cuda_arch=11", "^dependency-mv cuda_arch=11"],
             ["cuda_arch=10", "^dependency-mv cuda_arch=10"],
         ),
         (
-            "forward-multi-value +cuda cuda_arch=10,11 ^dependency-mv+cuda",
+            "forward-multi-value+cuda cuda_arch=10,11^dependency-mv+cuda",
             ["cuda_arch=10,11", "^dependency-mv cuda_arch=10,11"],
             [],
         ),
@@ -1073,9 +1074,9 @@ def test_forward_multi_valued_variant_using_requires(
     `requires` directives of the form:
 
         for _val in ("shared", "static"):
-            requires(f"^some-virtual-mv libs={_val}", when=f"libs={_val} ^some-virtual-mv")
+            requires(f"^some-virtual-mv libs={_val}", when=f"libs={_val}^some-virtual-mv")
     """
-    s = Spec(spec_str).concretized()
+    s = spack.concretize.concretize_one(spec_str)
 
     for constraint in expected:
         assert s.satisfies(constraint)
@@ -1086,7 +1087,7 @@ def test_forward_multi_valued_variant_using_requires(
 
 def test_strong_preferences_higher_priority_than_reuse(concretize_scope, mock_packages):
     """Tests that strong preferences have a higher priority than reusing specs."""
-    reused_spec = Spec("adios2~bzip2").concretized()
+    reused_spec = spack.concretize.concretize_one("adios2~bzip2")
     reuse_nodes = list(reused_spec.traverse())
     root_specs = [Spec("ascent+adios2")]
 
@@ -1121,7 +1122,7 @@ def test_strong_preferences_higher_priority_than_reuse(concretize_scope, mock_pa
         solver = spack.solver.asp.Solver()
         setup = spack.solver.asp.SpackSolverSetup()
         result, _, _ = solver.driver.solve(
-            setup, [Spec("ascent+adios2 ^adios2~bzip2")], reuse=reuse_nodes
+            setup, [Spec("ascent+adios2^adios2~bzip2")], reuse=reuse_nodes
         )
         ascent = result.specs[0]
     assert ascent["adios2"].dag_hash() == reused_spec.dag_hash(), ascent

lib/spack/spack/test/config_values.py

@@ -4,7 +4,7 @@
 
 import pytest
 
-import spack.spec
+import spack.concretize
 import spack.store
 
 
@@ -13,7 +13,7 @@
 def test_set_install_hash_length(hash_length, mutable_config, tmpdir):
     mutable_config.set("config:install_hash_length", hash_length)
     with spack.store.use_store(str(tmpdir)):
-        spec = spack.spec.Spec("libelf").concretized()
+        spec = spack.concretize.concretize_one("libelf")
         prefix = spec.prefix
         hash_str = prefix.rsplit("-")[-1]
         assert len(hash_str) == hash_length
@@ -23,7 +23,7 @@ def test_set_install_hash_length(hash_length, mutable_config, tmpdir):
 def test_set_install_hash_length_upper_case(mutable_config, tmpdir):
     mutable_config.set("config:install_hash_length", 5)
     with spack.store.use_store(str(tmpdir), extra_data={"projections": {"all": "{name}-{HASH}"}}):
-        spec = spack.spec.Spec("libelf").concretized()
+        spec = spack.concretize.concretize_one("libelf")
         prefix = spec.prefix
         hash_str = prefix.rsplit("-")[-1]
         assert len(hash_str) == 5

lib/spack/spack/test/conftest.py

@@ -36,6 +36,7 @@
 import spack.caches
 import spack.compiler
 import spack.compilers
+import spack.concretize
 import spack.config
 import spack.directives_meta
 import spack.environment as ev
@@ -849,7 +850,7 @@ def _populate(mock_db):
     """
 
     def _install(spec):
-        s = spack.spec.Spec(spec).concretized()
+        s = spack.concretize.concretize_one(spec)
         PackageInstaller([s.package], fake=True, explicit=True).install()
 
     _install("mpileaks ^mpich")
@@ -1983,7 +1984,9 @@ def default_mock_concretization(config, mock_packages, concretized_specs_cache):
     def _func(spec_str, tests=False):
         key = spec_str, tests
         if key not in concretized_specs_cache:
-            concretized_specs_cache[key] = spack.spec.Spec(spec_str).concretized(tests=tests)
+            concretized_specs_cache[key] = spack.concretize.concretize_one(
+                spack.spec.Spec(spec_str), tests=tests
+            )
         return concretized_specs_cache[key].copy()
 
     return _func

lib/spack/spack/test/cvs_fetch.py

@@ -8,8 +8,8 @@
 
 from llnl.util.filesystem import mkdirp, touch, working_dir
 
+import spack.concretize
 from spack.fetch_strategy import CvsFetchStrategy
-from spack.spec import Spec
 from spack.stage import Stage
 from spack.util.executable import which
 from spack.version import Version
@@ -37,7 +37,7 @@ def test_fetch(type_of_test, mock_cvs_repository, config, mutable_mock_repo):
     get_date = mock_cvs_repository.get_date
 
     # Construct the package under test
-    spec = Spec("cvs-test").concretized()
+    spec = spack.concretize.concretize_one("cvs-test")
     spec.package.versions[Version("cvs")] = test.args
 
     # Enter the stage directory and check some properties

lib/spack/spack/test/database.py

@@ -28,6 +28,7 @@
 import llnl.util.lock as lk
 from llnl.util.tty.colify import colify
 
+import spack.concretize
 import spack.database
 import spack.deptypes as dt
 import spack.package_base
@@ -108,8 +109,8 @@ def test_query_by_install_tree(
     up_db, down_db = upstream_and_downstream_db
 
     # Set the upstream DB to contain "pkg-c" and downstream to contain "pkg-b")
-    b = spack.spec.Spec("pkg-b").concretized()
+    b = spack.concretize.concretize_one("pkg-b")
-    c = spack.spec.Spec("pkg-c").concretized()
+    c = spack.concretize.concretize_one("pkg-c")
     with writable(up_db):
         up_db.add(c)
     up_db._read()
@@ -127,7 +128,7 @@ def test_spec_installed_upstream(
 
     # a known installed spec should say that it's installed
     with spack.repo.use_repositories(mock_custom_repository):
-        spec = spack.spec.Spec("pkg-c").concretized()
+        spec = spack.concretize.concretize_one("pkg-c")
         assert not spec.installed
         assert not spec.installed_upstream
 
@@ -157,7 +158,7 @@ def test_installed_upstream(upstream_and_downstream_db, tmpdir):
     builder.add_package("w", dependencies=[("x", None, None), ("y", None, None)])
 
     with spack.repo.use_repositories(builder.root):
-        spec = spack.spec.Spec("w").concretized()
+        spec = spack.concretize.concretize_one("w")
         with writable(upstream_db):
             for dep in spec.traverse(root=False):
                 upstream_db.add(dep)
@@ -169,7 +170,7 @@ def test_installed_upstream(upstream_and_downstream_db, tmpdir):
             with pytest.raises(spack.database.ForbiddenLockError):
                 upstream_db.get_by_hash(dep.dag_hash())
 
-        new_spec = spack.spec.Spec("w").concretized()
+        new_spec = spack.concretize.concretize_one("w")
         downstream_db.add(new_spec)
         for dep in new_spec.traverse(root=False):
             upstream, record = downstream_db.query_by_spec_hash(dep.dag_hash())
@@ -191,7 +192,7 @@ def test_removed_upstream_dep(upstream_and_downstream_db, tmpdir, capsys, config
     builder.add_package("y", dependencies=[("z", None, None)])
 
     with spack.repo.use_repositories(builder):
-        y = spack.spec.Spec("y").concretized()
+        y = spack.concretize.concretize_one("y")
         z = y["z"]
 
         # add dependency to upstream, dependents to downstream
@@ -225,7 +226,7 @@ def test_add_to_upstream_after_downstream(upstream_and_downstream_db, tmpdir):
     builder.add_package("x")
 
     with spack.repo.use_repositories(builder.root):
-        spec = spack.spec.Spec("x").concretized()
+        spec = spack.concretize.concretize_one("x")
 
         downstream_db.add(spec)
         with writable(upstream_db):
@@ -258,7 +259,7 @@ def test_cannot_write_upstream(tmp_path, mock_packages, config):
     db = spack.database.Database(str(tmp_path), is_upstream=True)
 
     with pytest.raises(spack.database.ForbiddenLockError):
-        db.add(spack.spec.Spec("pkg-a").concretized())
+        db.add(spack.concretize.concretize_one("pkg-a"))
 
 
 @pytest.mark.usefixtures("config", "temporary_store")
@@ -272,7 +273,7 @@ def test_recursive_upstream_dbs(tmpdir, gen_mock_layout):
     builder.add_package("x", dependencies=[("y", None, None)])
 
     with spack.repo.use_repositories(builder.root):
-        spec = spack.spec.Spec("x").concretized()
+        spec = spack.concretize.concretize_one("x")
         db_c = spack.database.Database(roots[2], layout=layouts[2])
         db_c.add(spec["z"])
 
@@ -422,7 +423,7 @@ def _check_remove_and_add_package(database: spack.database.Database, spec):
 
 
 def _mock_install(spec: str):
-    s = spack.spec.Spec(spec).concretized()
+    s = spack.concretize.concretize_one(spec)
     PackageInstaller([s.package], fake=True, explicit=True).install()
 
 
@@ -767,8 +768,7 @@ def test_regression_issue_8036(mutable_database, usr_folder_exists):
     # existing. Even when the package prefix exists, the package should
     # not be considered installed until it is added to the database by
     # the installer with install().
-    s = spack.spec.Spec("externaltool@0.9")
+    s = spack.concretize.concretize_one("externaltool@0.9")
-    s.concretize()
     assert not s.installed
 
     # Now install the external package and check again the `installed` property
@@ -783,8 +783,7 @@ def test_old_external_entries_prefix(mutable_database):
 
     jsonschema.validate(db_obj, schema)
 
-    s = spack.spec.Spec("externaltool")
+    s = spack.concretize.concretize_one("externaltool")
-    s.concretize()
 
     db_obj["database"]["installs"][s.dag_hash()]["path"] = "None"
 
@@ -813,8 +812,7 @@ def test_uninstall_by_spec(mutable_database):
 
 def test_query_unused_specs(mutable_database):
     # This spec installs a fake cmake as a build only dependency
-    s = spack.spec.Spec("simple-inheritance")
+    s = spack.concretize.concretize_one("simple-inheritance")
-    s.concretize()
     PackageInstaller([s.package], fake=True, explicit=True).install()
 
     si = s.dag_hash()
@@ -856,8 +854,7 @@ def check_unused(roots, deptype, expected):
 def test_query_spec_with_conditional_dependency(mutable_database):
     # The issue is triggered by having dependencies that are
     # conditional on a Boolean variant
-    s = spack.spec.Spec("hdf5~mpi")
+    s = spack.concretize.concretize_one("hdf5~mpi")
-    s.concretize()
     PackageInstaller([s.package], fake=True, explicit=True).install()
 
     results = spack.store.STORE.db.query_local("hdf5 ^mpich")
@@ -897,7 +894,7 @@ def _is(self, spec):
     # Pretend the spec has been failure locked
     monkeypatch.setattr(spack.database.FailureTracker, "lock_taken", _is)
 
-    s = spack.spec.Spec("pkg-a").concretized()
+    s = spack.concretize.concretize_one("pkg-a")
     spack.store.STORE.failure_tracker.clear(s)
     out = capfd.readouterr()[0]
     assert "Retaining failure marking" in out
@@ -915,7 +912,7 @@ def _is(self, spec):
     # Ensure raise OSError when try to remove the non-existent marking
     monkeypatch.setattr(spack.database.FailureTracker, "persistent_mark", _is)
 
-    s = spack.spec.Spec("pkg-a").concretized()
+    s = spack.concretize.concretize_one("pkg-a")
     spack.store.STORE.failure_tracker.clear(s, force=True)
     out = capfd.readouterr()[1]
     assert "Removing failure marking despite lock" in out
@@ -930,7 +927,7 @@ def _raise_exc(lock):
         raise lk.LockTimeoutError("write", "/mock-lock", 1.234, 10)
 
     with tmpdir.as_cwd():
-        s = spack.spec.Spec("pkg-a").concretized()
+        s = spack.concretize.concretize_one("pkg-a")
 
         # Ensure attempt to acquire write lock on the mark raises the exception
         monkeypatch.setattr(lk.Lock, "acquire_write", _raise_exc)
@@ -946,7 +943,7 @@ def _raise_exc(lock):
 def test_prefix_failed(mutable_database, monkeypatch):
     """Add coverage to failed operation."""
 
-    s = spack.spec.Spec("pkg-a").concretized()
+    s = spack.concretize.concretize_one("pkg-a")
 
     # Confirm the spec is not already marked as failed
     assert not spack.store.STORE.failure_tracker.has_failed(s)
@@ -970,7 +967,7 @@ def test_prefix_write_lock_error(mutable_database, monkeypatch):
     def _raise(db, spec):
         raise lk.LockError("Mock lock error")
 
-    s = spack.spec.Spec("pkg-a").concretized()
+    s = spack.concretize.concretize_one("pkg-a")
 
     # Ensure subsequent lock operations fail
     monkeypatch.setattr(lk.Lock, "acquire_write", _raise)
@@ -1178,7 +1175,7 @@ def test_reindex_with_upstreams(tmp_path, monkeypatch, mock_packages, config):
     # we install `mpileaks` locally with dependencies in the upstream. And we even install
     # `mpileaks` with the same hash in the upstream. After reindexing, `mpileaks` should still be
     # in the local db, and `callpath` should not.
-    mpileaks = spack.spec.Spec("mpileaks").concretized()
+    mpileaks = spack.concretize.concretize_one("mpileaks")
     callpath = mpileaks.dependencies("callpath")[0]
 
     upstream_store = spack.store.create(

lib/spack/spack/test/directives.py

@@ -5,6 +5,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.directives
 import spack.repo
 import spack.spec
@@ -59,8 +60,8 @@ def test_constraints_from_context_are_merged(mock_packages):
 
 @pytest.mark.regression("27754")
 def test_extends_spec(config, mock_packages):
-    extender = spack.spec.Spec("extends-spec").concretized()
+    extender = spack.concretize.concretize_one("extends-spec")
-    extendee = spack.spec.Spec("extendee").concretized()
+    extendee = spack.concretize.concretize_one("extendee")
 
     assert extender.dependencies
     assert extender.package.extends(extendee)
@@ -206,7 +207,7 @@ def test_repo(_create_test_repo, monkeypatch, mock_stage):
 def test_redistribute_directive(test_repo, spec_str, distribute_src, distribute_bin):
     spec = spack.spec.Spec(spec_str)
     assert spec.package_class.redistribute_source(spec) == distribute_src
-    concretized_spec = spec.concretized()
+    concretized_spec = spack.concretize.concretize_one(spec)
     assert concretized_spec.package.redistribute_binary == distribute_bin
 
 

lib/spack/spack/test/directory_layout.py

@@ -13,6 +13,7 @@
 
 from llnl.path import path_to_os_path
 
+import spack.concretize
 import spack.hash_types
 import spack.paths
 import spack.repo
@@ -59,7 +60,7 @@ def test_yaml_directory_layout_parameters(tmpdir, default_mock_concretization):
     assert package7 == path_package7
 
     # Test separation of architecture or namespace
-    spec2 = Spec("libelf").concretized()
+    spec2 = spack.concretize.concretize_one("libelf")
 
     arch_scheme = (
         "{architecture.platform}/{architecture.target}/{architecture.os}/{name}/{version}/{hash:7}"
@@ -97,7 +98,7 @@ def test_read_and_write_spec(temporary_store, config, mock_packages):
         # If a spec fails to concretize, just skip it.  If it is a
         # real error, it will be caught by concretization tests.
         try:
-            spec = spack.spec.Spec(name).concretized()
+            spec = spack.concretize.concretize_one(name)
         except Exception:
             continue
 
@@ -136,7 +137,7 @@ def test_read_and_write_spec(temporary_store, config, mock_packages):
         assert norm.eq_dag(spec_from_file)
 
         # TODO: revise this when build deps are in dag_hash
-        conc = read_separately.concretized().copy(deps=stored_deptypes)
+        conc = spack.concretize.concretize_one(read_separately).copy(deps=stored_deptypes)
         assert conc == spec_from_file
         assert conc.eq_dag(spec_from_file)
 
@@ -172,12 +173,10 @@ def test_handle_unknown_package(temporary_store, config, mock_packages, tmp_path
     # Create all the packages that are not in mock.
     installed_specs = {}
     for pkg_name in packages:
-        spec = spack.spec.Spec(pkg_name)
-
         # If a spec fails to concretize, just skip it.  If it is a
         # real error, it will be caught by concretization tests.
         try:
-            spec.concretize()
+            spec = spack.concretize.concretize_one(pkg_name)
         except Exception:
             continue
 
@@ -209,7 +208,7 @@ def test_find(temporary_store, config, mock_packages):
         if name.startswith("external"):
             # External package tests cannot be installed
             continue
-        spec = spack.spec.Spec(name).concretized()
+        spec = spack.concretize.concretize_one(name)
         installed_specs[spec.name] = spec
         layout.create_install_directory(spec)
 

lib/spack/spack/test/flag_handlers.py

@@ -7,7 +7,7 @@
 import pytest
 
 import spack.build_environment
-import spack.spec
+import spack.concretize
 from spack.package import build_system_flags, env_flags, inject_flags
 
 
@@ -30,10 +30,10 @@ def add_o3_to_build_system_cflags(pkg, name, flags):
 class TestFlagHandlers:
     def test_no_build_system_flags(self, temp_env):
         # Test that both autotools and cmake work getting no build_system flags
-        s1 = spack.spec.Spec("cmake-client").concretized()
+        s1 = spack.concretize.concretize_one("cmake-client")
         spack.build_environment.setup_package(s1.package, False)
 
-        s2 = spack.spec.Spec("patchelf").concretized()
+        s2 = spack.concretize.concretize_one("patchelf")
         spack.build_environment.setup_package(s2.package, False)
 
         # Use cppflags as a canary
@@ -43,28 +43,28 @@ def test_no_build_system_flags(self, temp_env):
     def test_unbound_method(self, temp_env):
         # Other tests test flag_handlers set as bound methods and functions.
         # This tests an unbound method in python2 (no change in python3).
-        s = spack.spec.Spec("mpileaks cppflags=-g").concretized()
+        s = spack.concretize.concretize_one("mpileaks cppflags=-g")
         s.package.flag_handler = s.package.__class__.inject_flags
         spack.build_environment.setup_package(s.package, False)
         assert os.environ["SPACK_CPPFLAGS"] == "-g"
         assert "CPPFLAGS" not in os.environ
 
     def test_inject_flags(self, temp_env):
-        s = spack.spec.Spec("mpileaks cppflags=-g").concretized()
+        s = spack.concretize.concretize_one("mpileaks cppflags=-g")
         s.package.flag_handler = inject_flags
         spack.build_environment.setup_package(s.package, False)
         assert os.environ["SPACK_CPPFLAGS"] == "-g"
         assert "CPPFLAGS" not in os.environ
 
     def test_env_flags(self, temp_env):
-        s = spack.spec.Spec("mpileaks cppflags=-g").concretized()
+        s = spack.concretize.concretize_one("mpileaks cppflags=-g")
         s.package.flag_handler = env_flags
         spack.build_environment.setup_package(s.package, False)
         assert os.environ["CPPFLAGS"] == "-g"
         assert "SPACK_CPPFLAGS" not in os.environ
 
     def test_build_system_flags_cmake(self, temp_env):
-        s = spack.spec.Spec("cmake-client cppflags=-g").concretized()
+        s = spack.concretize.concretize_one("cmake-client cppflags=-g")
         s.package.flag_handler = build_system_flags
         spack.build_environment.setup_package(s.package, False)
         assert "SPACK_CPPFLAGS" not in os.environ
@@ -76,7 +76,7 @@ def test_build_system_flags_cmake(self, temp_env):
         }
 
     def test_build_system_flags_autotools(self, temp_env):
-        s = spack.spec.Spec("patchelf cppflags=-g").concretized()
+        s = spack.concretize.concretize_one("patchelf cppflags=-g")
         s.package.flag_handler = build_system_flags
         spack.build_environment.setup_package(s.package, False)
         assert "SPACK_CPPFLAGS" not in os.environ
@@ -85,7 +85,7 @@ def test_build_system_flags_autotools(self, temp_env):
 
     def test_build_system_flags_not_implemented(self, temp_env):
         """Test the command line flags method raises a NotImplementedError"""
-        s = spack.spec.Spec("mpileaks cppflags=-g").concretized()
+        s = spack.concretize.concretize_one("mpileaks cppflags=-g")
         s.package.flag_handler = build_system_flags
         try:
             spack.build_environment.setup_package(s.package, False)
@@ -94,7 +94,7 @@ def test_build_system_flags_not_implemented(self, temp_env):
             assert True
 
     def test_add_build_system_flags_autotools(self, temp_env):
-        s = spack.spec.Spec("patchelf cppflags=-g").concretized()
+        s = spack.concretize.concretize_one("patchelf cppflags=-g")
         s.package.flag_handler = add_o3_to_build_system_cflags
         spack.build_environment.setup_package(s.package, False)
         assert "-g" in os.environ["SPACK_CPPFLAGS"]
@@ -102,7 +102,7 @@ def test_add_build_system_flags_autotools(self, temp_env):
         assert s.package.configure_flag_args == ["CFLAGS=-O3"]
 
     def test_add_build_system_flags_cmake(self, temp_env):
-        s = spack.spec.Spec("cmake-client cppflags=-g").concretized()
+        s = spack.concretize.concretize_one("cmake-client cppflags=-g")
         s.package.flag_handler = add_o3_to_build_system_cflags
         spack.build_environment.setup_package(s.package, False)
         assert "-g" in os.environ["SPACK_CPPFLAGS"]
@@ -110,7 +110,7 @@ def test_add_build_system_flags_cmake(self, temp_env):
         assert s.package.cmake_flag_args == ["-DCMAKE_C_FLAGS=-O3"]
 
     def test_ld_flags_cmake(self, temp_env):
-        s = spack.spec.Spec("cmake-client ldflags=-mthreads").concretized()
+        s = spack.concretize.concretize_one("cmake-client ldflags=-mthreads")
         s.package.flag_handler = build_system_flags
         spack.build_environment.setup_package(s.package, False)
         assert "SPACK_LDFLAGS" not in os.environ
@@ -122,7 +122,7 @@ def test_ld_flags_cmake(self, temp_env):
         }
 
     def test_ld_libs_cmake(self, temp_env):
-        s = spack.spec.Spec("cmake-client ldlibs=-lfoo").concretized()
+        s = spack.concretize.concretize_one("cmake-client ldlibs=-lfoo")
         s.package.flag_handler = build_system_flags
         spack.build_environment.setup_package(s.package, False)
         assert "SPACK_LDLIBS" not in os.environ
@@ -138,7 +138,7 @@ def test_flag_handler(self, name, flags):
             flags.append("-foo")
             return (flags, None, None)
 
-        s = spack.spec.Spec("cmake-client").concretized()
+        s = spack.concretize.concretize_one("cmake-client")
         s.package.flag_handler = test_flag_handler
         spack.build_environment.setup_package(s.package, False)
 

lib/spack/spack/test/git_fetch.py

@@ -10,6 +10,7 @@
 
 from llnl.util.filesystem import mkdirp, touch, working_dir
 
+import spack.concretize
 import spack.config
 import spack.error
 import spack.fetch_strategy
@@ -185,8 +186,9 @@ def test_adhoc_version_submodules(
     monkeypatch.setitem(pkg_class.versions, Version("git"), t.args)
     monkeypatch.setattr(pkg_class, "git", "file://%s" % mock_git_repository.path, raising=False)
 
-    spec = Spec("git-test@{0}".format(mock_git_repository.unversioned_commit))
+    spec = spack.concretize.concretize_one(
-    spec.concretize()
+        Spec("git-test@{0}".format(mock_git_repository.unversioned_commit))
+    )
     spec.package.do_stage()
     collected_fnames = set()
     for root, dirs, files in os.walk(spec.package.stage.source_path):

lib/spack/spack/test/graph.py

@@ -3,8 +3,8 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 import io
 
+import spack.concretize
 import spack.graph
-import spack.spec
 
 
 def test_dynamic_dot_graph_mpileaks(default_mock_concretization):
@@ -38,7 +38,7 @@ def test_dynamic_dot_graph_mpileaks(default_mock_concretization):
 
 def test_ascii_graph_mpileaks(config, mock_packages, monkeypatch):
     monkeypatch.setattr(spack.graph.AsciiGraph, "_node_label", lambda self, node: node.name)
-    s = spack.spec.Spec("mpileaks").concretized()
+    s = spack.concretize.concretize_one("mpileaks")
 
     stream = io.StringIO()
     graph = spack.graph.AsciiGraph()

lib/spack/spack/test/hg_fetch.py

@@ -8,9 +8,9 @@
 
 from llnl.util.filesystem import mkdirp, touch, working_dir
 
+import spack.concretize
 import spack.config
 from spack.fetch_strategy import HgFetchStrategy
-from spack.spec import Spec
 from spack.stage import Stage
 from spack.util.executable import which
 from spack.version import Version
@@ -40,7 +40,7 @@ def test_fetch(type_of_test, secure, mock_hg_repository, config, mutable_mock_re
     h = mock_hg_repository.hash
 
     # Construct the package under test
-    s = Spec("hg-test").concretized()
+    s = spack.concretize.concretize_one("hg-test")
     monkeypatch.setitem(s.package.versions, Version("hg"), t.args)
 
     # Enter the stage directory and check some properties

lib/spack/spack/test/install.py

@@ -11,6 +11,7 @@
 import llnl.util.filesystem as fs
 
 import spack.build_environment
+import spack.concretize
 import spack.config
 import spack.database
 import spack.error
@@ -41,7 +42,7 @@ def find_nothing(*args):
 
 
 def test_install_and_uninstall(install_mockery, mock_fetch, monkeypatch):
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
 
     PackageInstaller([spec.package], explicit=True).install()
     assert spec.installed
@@ -53,7 +54,7 @@ def test_install_and_uninstall(install_mockery, mock_fetch, monkeypatch):
 @pytest.mark.regression("11870")
 def test_uninstall_non_existing_package(install_mockery, mock_fetch, monkeypatch):
     """Ensure that we can uninstall a package that has been deleted from the repo"""
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
 
     PackageInstaller([spec.package], explicit=True).install()
     assert spec.installed
@@ -71,8 +72,7 @@ def test_uninstall_non_existing_package(install_mockery, mock_fetch, monkeypatch
 
 def test_pkg_attributes(install_mockery, mock_fetch, monkeypatch):
     # Get a basic concrete spec for the dummy package.
-    spec = Spec("attributes-foo-app ^attributes-foo")
+    spec = spack.concretize.concretize_one("attributes-foo-app ^attributes-foo")
-    spec.concretize()
     assert spec.concrete
 
     pkg = spec.package
@@ -127,7 +127,7 @@ def remove_prefix(self):
 
 
 def test_partial_install_delete_prefix_and_stage(install_mockery, mock_fetch, working_env):
-    s = Spec("canfail").concretized()
+    s = spack.concretize.concretize_one("canfail")
 
     instance_rm_prefix = s.package.remove_prefix
 
@@ -157,7 +157,7 @@ def test_failing_overwrite_install_should_keep_previous_installation(
     the original install prefix instead of cleaning it.
     """
     # Do a successful install
-    s = Spec("canfail").concretized()
+    s = spack.concretize.concretize_one("canfail")
     s.package.set_install_succeed()
 
     # Do a failing overwrite install
@@ -173,13 +173,11 @@ def test_failing_overwrite_install_should_keep_previous_installation(
 
 
 def test_dont_add_patches_to_installed_package(install_mockery, mock_fetch, monkeypatch):
-    dependency = Spec("dependency-install")
+    dependency = spack.concretize.concretize_one("dependency-install")
-    dependency.concretize()
     PackageInstaller([dependency.package], explicit=True).install()
 
     dependency_hash = dependency.dag_hash()
-    dependent = Spec("dependent-install ^/" + dependency_hash)
+    dependent = spack.concretize.concretize_one("dependent-install ^/" + dependency_hash)
-    dependent.concretize()
 
     monkeypatch.setitem(
         dependency.package.patches,
@@ -191,20 +189,18 @@ def test_dont_add_patches_to_installed_package(install_mockery, mock_fetch, monk
 
 
 def test_installed_dependency_request_conflicts(install_mockery, mock_fetch, mutable_mock_repo):
-    dependency = Spec("dependency-install")
+    dependency = spack.concretize.concretize_one("dependency-install")
-    dependency.concretize()
     PackageInstaller([dependency.package], explicit=True).install()
 
     dependency_hash = dependency.dag_hash()
     dependent = Spec("conflicting-dependent ^/" + dependency_hash)
     with pytest.raises(spack.error.UnsatisfiableSpecError):
-        dependent.concretize()
+        spack.concretize.concretize_one(dependent)
 
 
 def test_install_dependency_symlinks_pkg(install_mockery, mock_fetch, mutable_mock_repo):
     """Test dependency flattening/symlinks mock package."""
-    spec = Spec("flatten-deps")
+    spec = spack.concretize.concretize_one("flatten-deps")
-    spec.concretize()
     pkg = spec.package
     PackageInstaller([pkg], explicit=True).install()
 
@@ -215,7 +211,7 @@ def test_install_dependency_symlinks_pkg(install_mockery, mock_fetch, mutable_mo
 
 def test_install_times(install_mockery, mock_fetch, mutable_mock_repo):
     """Test install times added."""
-    spec = Spec("dev-build-test-install-phases").concretized()
+    spec = spack.concretize.concretize_one("dev-build-test-install-phases")
     PackageInstaller([spec.package], explicit=True).install()
 
     # Ensure dependency directory exists after the installation.
@@ -236,8 +232,7 @@ def test_flatten_deps(install_mockery, mock_fetch, mutable_mock_repo):
     """Explicitly test the flattening code for coverage purposes."""
     # Unfortunately, executing the 'flatten-deps' spec's installation does
     # not affect code coverage results, so be explicit here.
-    spec = Spec("dependent-install")
+    spec = spack.concretize.concretize_one("dependent-install")
-    spec.concretize()
     pkg = spec.package
     PackageInstaller([pkg], explicit=True).install()
 
@@ -272,7 +267,7 @@ def install_upstream(tmpdir_factory, gen_mock_layout, install_mockery):
 
     def _install_upstream(*specs):
         for spec_str in specs:
-            prepared_db.add(Spec(spec_str).concretized())
+            prepared_db.add(spack.concretize.concretize_one(spec_str))
         downstream_root = str(tmpdir_factory.mktemp("mock_downstream_db_root"))
         return downstream_root, upstream_layout
 
@@ -285,8 +280,7 @@ def test_installed_upstream_external(install_upstream, mock_fetch):
     """
     store_root, _ = install_upstream("externaltool")
     with spack.store.use_store(store_root):
-        dependent = Spec("externaltest")
+        dependent = spack.concretize.concretize_one("externaltest")
-        dependent.concretize()
 
         new_dependency = dependent["externaltool"]
         assert new_dependency.external
@@ -304,8 +298,8 @@ def test_installed_upstream(install_upstream, mock_fetch):
     """
     store_root, upstream_layout = install_upstream("dependency-install")
     with spack.store.use_store(store_root):
-        dependency = Spec("dependency-install").concretized()
+        dependency = spack.concretize.concretize_one("dependency-install")
-        dependent = Spec("dependent-install").concretized()
+        dependent = spack.concretize.concretize_one("dependent-install")
 
         new_dependency = dependent["dependency-install"]
         assert new_dependency.installed_upstream
@@ -319,7 +313,7 @@ def test_installed_upstream(install_upstream, mock_fetch):
 
 @pytest.mark.disable_clean_stage_check
 def test_partial_install_keep_prefix(install_mockery, mock_fetch, monkeypatch, working_env):
-    s = Spec("canfail").concretized()
+    s = spack.concretize.concretize_one("canfail")
 
     # If remove_prefix is called at any point in this test, that is an error
     monkeypatch.setattr(spack.package_base.PackageBase, "remove_prefix", mock_remove_prefix)
@@ -336,7 +330,7 @@ def test_partial_install_keep_prefix(install_mockery, mock_fetch, monkeypatch, w
 
 
 def test_second_install_no_overwrite_first(install_mockery, mock_fetch, monkeypatch):
-    s = Spec("canfail").concretized()
+    s = spack.concretize.concretize_one("canfail")
     monkeypatch.setattr(spack.package_base.PackageBase, "remove_prefix", mock_remove_prefix)
 
     s.package.set_install_succeed()
@@ -356,8 +350,8 @@ def test_install_prefix_collision_fails(config, mock_fetch, mock_packages, tmpdi
     projections = {"projections": {"all": "one-prefix-per-package-{name}"}}
     with spack.store.use_store(str(tmpdir), extra_data=projections):
         with spack.config.override("config:checksum", False):
-            pkg_a = Spec("libelf@0.8.13").concretized().package
+            pkg_a = spack.concretize.concretize_one("libelf@0.8.13").package
-            pkg_b = Spec("libelf@0.8.12").concretized().package
+            pkg_b = spack.concretize.concretize_one("libelf@0.8.12").package
             PackageInstaller([pkg_a], explicit=True, fake=True).install()
 
             with pytest.raises(InstallError, match="Install prefix collision"):
@@ -365,14 +359,14 @@ def test_install_prefix_collision_fails(config, mock_fetch, mock_packages, tmpdi
 
 
 def test_store(install_mockery, mock_fetch):
-    spec = Spec("cmake-client").concretized()
+    spec = spack.concretize.concretize_one("cmake-client")
     pkg = spec.package
     PackageInstaller([pkg], fake=True, explicit=True).install()
 
 
 @pytest.mark.disable_clean_stage_check
 def test_failing_build(install_mockery, mock_fetch, capfd):
-    spec = Spec("failing-build").concretized()
+    spec = spack.concretize.concretize_one("failing-build")
     pkg = spec.package
 
     with pytest.raises(spack.build_environment.ChildError, match="Expected failure"):
@@ -387,8 +381,7 @@ def test_uninstall_by_spec_errors(mutable_database):
     """Test exceptional cases with the uninstall command."""
 
     # Try to uninstall a spec that has not been installed
-    spec = Spec("dependent-install")
+    spec = spack.concretize.concretize_one("dependent-install")
-    spec.concretize()
     with pytest.raises(InstallError, match="is not installed"):
         PackageBase.uninstall_by_spec(spec)
 
@@ -401,7 +394,7 @@ def test_uninstall_by_spec_errors(mutable_database):
 @pytest.mark.disable_clean_stage_check
 def test_nosource_pkg_install(install_mockery, mock_fetch, mock_packages, capfd, ensure_debug):
     """Test install phases with the nosource package."""
-    spec = Spec("nosource").concretized()
+    spec = spack.concretize.concretize_one("nosource")
     pkg = spec.package
 
     # Make sure install works even though there is no associated code.
@@ -418,7 +411,7 @@ def test_nosource_bundle_pkg_install(
     install_mockery, mock_fetch, mock_packages, capfd, ensure_debug
 ):
     """Test install phases with the nosource-bundle package."""
-    spec = Spec("nosource-bundle").concretized()
+    spec = spack.concretize.concretize_one("nosource-bundle")
     pkg = spec.package
 
     # Make sure install works even though there is no associated code.
@@ -432,7 +425,7 @@ def test_nosource_bundle_pkg_install(
 
 def test_nosource_pkg_install_post_install(install_mockery, mock_fetch, mock_packages):
     """Test install phases with the nosource package with post-install."""
-    spec = Spec("nosource-install").concretized()
+    spec = spack.concretize.concretize_one("nosource-install")
     pkg = spec.package
 
     # Make sure both the install and post-install package methods work.
@@ -449,14 +442,14 @@ def test_nosource_pkg_install_post_install(install_mockery, mock_fetch, mock_pac
 
 def test_pkg_build_paths(install_mockery):
     # Get a basic concrete spec for the trivial install package.
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
     assert spec.package.log_path.endswith(_spack_build_logfile)
     assert spec.package.env_path.endswith(_spack_build_envfile)
 
 
 def test_pkg_install_paths(install_mockery):
     # Get a basic concrete spec for the trivial install package.
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
 
     log_path = os.path.join(spec.prefix, ".spack", _spack_build_logfile + ".gz")
     assert spec.package.install_log_path == log_path
@@ -493,7 +486,7 @@ def test_pkg_install_paths(install_mockery):
 def test_log_install_without_build_files(install_mockery):
     """Test the installer log function when no build files are present."""
     # Get a basic concrete spec for the trivial install package.
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
 
     # Attempt installing log without the build log file
     with pytest.raises(IOError, match="No such file or directory"):
@@ -515,7 +508,7 @@ def _install(src, dest):
 
     monkeypatch.setattr(fs, "install", _install)
 
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
 
     # Set up mock build files and try again to include archive failure
     log_path = spec.package.log_path
@@ -587,7 +580,7 @@ def test_empty_install_sanity_check_prefix(
     monkeypatch, install_mockery, mock_fetch, mock_packages
 ):
     """Test empty install triggers sanity_check_prefix."""
-    spec = Spec("failing-empty-install").concretized()
+    spec = spack.concretize.concretize_one("failing-empty-install")
     with pytest.raises(spack.build_environment.ChildError, match="Nothing was installed"):
         PackageInstaller([spec.package], explicit=True).install()
 
@@ -599,7 +592,7 @@ def test_install_from_binary_with_missing_patch_succeeds(
     pushing the package to a binary cache, installation from that binary cache shouldn't error out
     because of the missing patch."""
     # Create a spec s with non-existing patches
-    s = Spec("trivial-install-test-package").concretized()
+    s = spack.concretize.concretize_one("trivial-install-test-package")
     patches = ["a" * 64]
     s_dict = s.to_dict()
     s_dict["spec"]["nodes"][0]["patches"] = patches

lib/spack/spack/test/installer.py

@@ -16,6 +16,7 @@
 import llnl.util.tty as tty
 
 import spack.binary_distribution
+import spack.concretize
 import spack.database
 import spack.deptypes as dt
 import spack.error
@@ -81,7 +82,7 @@ def create_installer(
 ) -> inst.PackageInstaller:
     """Create an installer instance for a list of specs or package names that will be
     concretized."""
-    _specs = [spack.spec.Spec(s).concretized() if isinstance(s, str) else s for s in specs]
+    _specs = [spack.concretize.concretize_one(s) if isinstance(s, str) else s for s in specs]
     _install_args = {} if install_args is None else install_args
     return inst.PackageInstaller([spec.package for spec in _specs], **_install_args)
 
@@ -96,8 +97,7 @@ def test_hms(sec, result):
 
 def test_get_dependent_ids(install_mockery, mock_packages):
     # Concretize the parent package, which handle dependency too
-    spec = spack.spec.Spec("pkg-a")
+    spec = spack.concretize.concretize_one("pkg-a")
-    spec.concretize()
     assert spec.concrete
 
     pkg_id = inst.package_id(spec)
@@ -133,8 +133,7 @@ def test_install_msg(monkeypatch):
 
 def test_install_from_cache_errors(install_mockery):
     """Test to ensure cover install from cache errors."""
-    spec = spack.spec.Spec("trivial-install-test-package")
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
-    spec.concretize()
     assert spec.concrete
 
     # Check with cache-only
@@ -153,8 +152,7 @@ def test_install_from_cache_errors(install_mockery):
 
 def test_install_from_cache_ok(install_mockery, monkeypatch):
     """Test to ensure cover _install_from_cache to the return."""
-    spec = spack.spec.Spec("trivial-install-test-package")
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
-    spec.concretize()
     monkeypatch.setattr(inst, "_try_install_from_binary_cache", _true)
     monkeypatch.setattr(spack.hooks, "post_install", _noop)
 
@@ -163,8 +161,7 @@ def test_install_from_cache_ok(install_mockery, monkeypatch):
 
 def test_process_external_package_module(install_mockery, monkeypatch, capfd):
     """Test to simply cover the external module message path."""
-    spec = spack.spec.Spec("trivial-install-test-package")
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
-    spec.concretize()
     assert spec.concrete
 
     # Ensure take the external module path WITHOUT any changes to the database
@@ -191,7 +188,7 @@ def _spec(spec, unsigned=False, mirrors_for_spec=None):
     # Skip database updates
     monkeypatch.setattr(spack.database.Database, "add", _noop)
 
-    spec = spack.spec.Spec("pkg-a").concretized()
+    spec = spack.concretize.concretize_one("pkg-a")
     assert inst._process_binary_cache_tarball(spec.package, explicit=False, unsigned=False)
 
     out = capfd.readouterr()[0]
@@ -201,8 +198,7 @@ def _spec(spec, unsigned=False, mirrors_for_spec=None):
 
 def test_try_install_from_binary_cache(install_mockery, mock_packages, monkeypatch):
     """Test return false when no match exists in the mirror"""
-    spec = spack.spec.Spec("mpich")
+    spec = spack.concretize.concretize_one("mpich")
-    spec.concretize()
     result = inst._try_install_from_binary_cache(spec.package, False, False)
     assert not result
 
@@ -274,7 +270,7 @@ def _mock_installed(self):
 
 
 def test_check_before_phase_error(install_mockery):
-    s = spack.spec.Spec("trivial-install-test-package").concretized()
+    s = spack.concretize.concretize_one("trivial-install-test-package")
     s.package.stop_before_phase = "beforephase"
     with pytest.raises(inst.BadInstallPhase) as exc_info:
         inst._check_last_phase(s.package)
@@ -285,7 +281,7 @@ def test_check_before_phase_error(install_mockery):
 
 
 def test_check_last_phase_error(install_mockery):
-    s = spack.spec.Spec("trivial-install-test-package").concretized()
+    s = spack.concretize.concretize_one("trivial-install-test-package")
     s.package.stop_before_phase = None
     s.package.last_phase = "badphase"
     with pytest.raises(inst.BadInstallPhase) as exc_info:
@@ -420,15 +416,13 @@ def test_package_id_err(install_mockery):
 
 
 def test_package_id_ok(install_mockery):
-    spec = spack.spec.Spec("trivial-install-test-package")
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
-    spec.concretize()
     assert spec.concrete
     assert spec.name in inst.package_id(spec)
 
 
 def test_fake_install(install_mockery):
-    spec = spack.spec.Spec("trivial-install-test-package")
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
-    spec.concretize()
     assert spec.concrete
 
     pkg = spec.package
@@ -440,7 +434,7 @@ def test_dump_packages_deps_ok(install_mockery, tmpdir, mock_packages):
     """Test happy path for dump_packages with dependencies."""
 
     spec_name = "simple-inheritance"
-    spec = spack.spec.Spec(spec_name).concretized()
+    spec = spack.concretize.concretize_one(spec_name)
     inst.dump_packages(spec, str(tmpdir))
 
     repo = mock_packages.repos[0]
@@ -471,7 +465,7 @@ def _repoerr(repo, name):
     # the try-except block
     monkeypatch.setattr(spack.store.STORE.layout, "build_packages_path", bpp_path)
 
-    spec = spack.spec.Spec("simple-inheritance").concretized()
+    spec = spack.concretize.concretize_one("simple-inheritance")
     path = str(tmpdir)
 
     # The call to install_tree will raise the exception since not mocking
@@ -581,7 +575,7 @@ def test_check_deps_status_install_failure(install_mockery):
     """Tests that checking the dependency status on a request to install
     'a' fails, if we mark the dependency as failed.
     """
-    s = spack.spec.Spec("pkg-a").concretized()
+    s = spack.concretize.concretize_one("pkg-a")
     for dep in s.traverse(root=False):
         spack.store.STORE.failure_tracker.mark(dep)
 
@@ -654,8 +648,8 @@ def test_installer_init_requests(install_mockery):
 @pytest.mark.parametrize("transitive", [True, False])
 def test_install_spliced(install_mockery, mock_fetch, monkeypatch, capsys, transitive):
     """Test installing a spliced spec"""
-    spec = spack.spec.Spec("splice-t").concretized()
+    spec = spack.concretize.concretize_one("splice-t")
-    dep = spack.spec.Spec("splice-h+foo").concretized()
+    dep = spack.concretize.concretize_one("splice-h+foo")
 
     # Do the splice.
     out = spec.splice(dep, transitive)
@@ -669,8 +663,8 @@ def test_install_spliced(install_mockery, mock_fetch, monkeypatch, capsys, trans
 @pytest.mark.parametrize("transitive", [True, False])
 def test_install_spliced_build_spec_installed(install_mockery, capfd, mock_fetch, transitive):
     """Test installing a spliced spec with the build spec already installed"""
-    spec = spack.spec.Spec("splice-t").concretized()
+    spec = spack.concretize.concretize_one("splice-t")
-    dep = spack.spec.Spec("splice-h+foo").concretized()
+    dep = spack.concretize.concretize_one("splice-h+foo")
 
     # Do the splice.
     out = spec.splice(dep, transitive)
@@ -696,8 +690,8 @@ def test_install_splice_root_from_binary(
 ):
     """Test installing a spliced spec with the root available in binary cache"""
     # Test splicing and rewiring a spec with the same name, different hash.
-    original_spec = spack.spec.Spec(root_str).concretized()
+    original_spec = spack.concretize.concretize_one(root_str)
-    spec_to_splice = spack.spec.Spec("splice-h+foo").concretized()
+    spec_to_splice = spack.concretize.concretize_one("splice-h+foo")
 
     PackageInstaller([original_spec.package, spec_to_splice.package]).install()
 
@@ -853,7 +847,7 @@ def _chgrp(path, group, follow_symlinks=True):
     monkeypatch.setattr(fs, "chgrp", _chgrp)
 
     build_task = create_build_task(
-        spack.spec.Spec("trivial-install-test-package").concretized().package
+        spack.concretize.concretize_one("trivial-install-test-package").package
     )
     spec = build_task.request.pkg.spec
 
@@ -1024,7 +1018,8 @@ def test_install_fail_multi(install_mockery, mock_fetch, monkeypatch):
 
 def test_install_fail_fast_on_detect(install_mockery, monkeypatch, capsys):
     """Test fail_fast install when an install failure is detected."""
-    b, c = spack.spec.Spec("pkg-b").concretized(), spack.spec.Spec("pkg-c").concretized()
+    b = spack.concretize.concretize_one("pkg-b")
+    c = spack.concretize.concretize_one("pkg-c")
     b_id, c_id = inst.package_id(b), inst.package_id(c)
 
     installer = create_installer([b, c], {"fail_fast": True})
@@ -1093,7 +1088,7 @@ def _requeued(installer, task, install_status):
 
 def test_install_lock_installed_requeue(install_mockery, monkeypatch, capfd):
     """Cover basic install handling for installed package."""
-    b = spack.spec.Spec("pkg-b").concretized()
+    b = spack.concretize.concretize_one("pkg-b")
     b_pkg_id = inst.package_id(b)
     installer = create_installer([b])
 
@@ -1279,7 +1274,7 @@ def test_term_status_line():
 @pytest.mark.parametrize("explicit", [True, False])
 def test_single_external_implicit_install(install_mockery, explicit):
     pkg = "trivial-install-test-package"
-    s = spack.spec.Spec(pkg).concretized()
+    s = spack.concretize.concretize_one(pkg)
     s.external_path = "/usr"
     args = {"explicit": [s.dag_hash()] if explicit else []}
     create_installer([s], args).install()
@@ -1288,7 +1283,7 @@ def test_single_external_implicit_install(install_mockery, explicit):
 
 def test_overwrite_install_does_install_build_deps(install_mockery, mock_fetch):
     """When overwrite installing something from sources, build deps should be installed."""
-    s = spack.spec.Spec("dtrun3").concretized()
+    s = spack.concretize.concretize_one("dtrun3")
     create_installer([s]).install()
 
     # Verify there is a pure build dep
@@ -1310,7 +1305,7 @@ def test_overwrite_install_does_install_build_deps(install_mockery, mock_fetch):
 def test_print_install_test_log_skipped(install_mockery, mock_packages, capfd, run_tests):
     """Confirm printing of install log skipped if not run/no failures."""
     name = "trivial-install-test-package"
-    s = spack.spec.Spec(name).concretized()
+    s = spack.concretize.concretize_one(name)
     pkg = s.package
 
     pkg.run_tests = run_tests
@@ -1324,7 +1319,7 @@ def test_print_install_test_log_failures(
 ):
     """Confirm expected outputs when there are test failures."""
     name = "trivial-install-test-package"
-    s = spack.spec.Spec(name).concretized()
+    s = spack.concretize.concretize_one(name)
     pkg = s.package
 
     # Missing test log is an error

lib/spack/spack/test/mirror.py

@@ -11,6 +11,7 @@
 from llnl.util.symlink import resolve_link_target_relative_to_the_link
 
 import spack.caches
+import spack.concretize
 import spack.config
 import spack.fetch_strategy
 import spack.mirrors.layout
@@ -43,7 +44,7 @@ def set_up_package(name, repository, url_attr):
     2. Point the package's version args at that repo.
     """
     # Set up packages to point at mock repos.
-    s = Spec(name).concretized()
+    s = spack.concretize.concretize_one(name)
     repos[name] = repository
 
     # change the fetch args of the first (only) version.
@@ -60,7 +61,7 @@ def check_mirror():
         mirrors = {"spack-mirror-test": url_util.path_to_file_url(mirror_root)}
         with spack.config.override("mirrors", mirrors):
             with spack.config.override("config:checksum", False):
-                specs = [Spec(x).concretized() for x in repos]
+                specs = [spack.concretize.concretize_one(x) for x in repos]
                 spack.mirrors.utils.create(mirror_root, specs)
 
             # Stage directory exists
@@ -77,7 +78,7 @@ def check_mirror():
 
             # Now try to fetch each package.
             for name, mock_repo in repos.items():
-                spec = Spec(name).concretized()
+                spec = spack.concretize.concretize_one(name)
                 pkg = spec.package
 
                 with spack.config.override("config:checksum", False):
@@ -212,13 +213,15 @@ def test_invalid_json_mirror_collection(invalid_json, error_message):
 
 
 def test_mirror_archive_paths_no_version(mock_packages, mock_archive):
-    spec = Spec("trivial-install-test-package@=nonexistingversion").concretized()
+    spec = spack.concretize.concretize_one(
+        Spec("trivial-install-test-package@=nonexistingversion")
+    )
     fetcher = spack.fetch_strategy.URLFetchStrategy(url=mock_archive.url)
     spack.mirrors.layout.default_mirror_layout(fetcher, "per-package-ref", spec)
 
 
 def test_mirror_with_url_patches(mock_packages, monkeypatch):
-    spec = Spec("patch-several-dependencies").concretized()
+    spec = spack.concretize.concretize_one("patch-several-dependencies")
     files_cached_in_mirror = set()
 
     def record_store(_class, fetcher, relative_dst, cosmetic_path=None):

lib/spack/spack/test/modules/common.py

@@ -9,6 +9,7 @@
 from llnl.util.symlink import readlink
 
 import spack.cmd.modules
+import spack.concretize
 import spack.config
 import spack.error
 import spack.modules
@@ -17,10 +18,8 @@
 import spack.package_base
 import spack.package_prefs
 import spack.repo
-import spack.spec
 from spack.installer import PackageInstaller
 from spack.modules.common import UpstreamModuleIndex
-from spack.spec import Spec
 
 pytestmark = [
     pytest.mark.not_on_windows("does not run on windows"),
@@ -60,7 +59,7 @@ def mock_package_perms(monkeypatch):
 def test_modules_written_with_proper_permissions(
     mock_module_filename, mock_package_perms, mock_packages, config
 ):
-    spec = spack.spec.Spec("mpileaks").concretized()
+    spec = spack.concretize.concretize_one("mpileaks")
 
     # The code tested is common to all module types, but has to be tested from
     # one. Tcl picked at random
@@ -74,7 +73,7 @@ def test_modules_written_with_proper_permissions(
 def test_modules_default_symlink(
     module_type, mock_packages, mock_module_filename, mock_module_defaults, config
 ):
-    spec = spack.spec.Spec("mpileaks@2.3").concretized()
+    spec = spack.concretize.concretize_one("mpileaks@2.3")
     mock_module_defaults(spec.format("{name}{@version}"), True)
 
     generator_cls = spack.modules.module_types[module_type]
@@ -180,7 +179,7 @@ def test_get_module_upstream():
 @pytest.mark.regression("14347")
 def test_load_installed_package_not_in_repo(install_mockery, mock_fetch, monkeypatch):
     """Test that installed packages that have been removed are still loadable"""
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
     PackageInstaller([spec.package], explicit=True).install()
     spack.modules.module_types["tcl"](spec, "default", True).write()
 

lib/spack/spack/test/modules/conftest.py

@@ -5,6 +5,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.modules.lmod
 import spack.modules.tcl
 import spack.spec
@@ -18,7 +19,7 @@ def modulefile_content(request):
     def _impl(spec_like, module_set_name="default", explicit=True):
         if isinstance(spec_like, str):
             spec_like = spack.spec.Spec(spec_like)
-        spec = spec_like.concretized()
+        spec = spack.concretize.concretize_one(spec_like)
         generator = writer_cls(spec, module_set_name, explicit)
         generator.write(overwrite=True)
         written_module = pathlib.Path(generator.layout.filename)
@@ -35,7 +36,7 @@ def factory(request, mock_modules_root):
     writer_cls = getattr(request.module, "writer_cls")
 
     def _mock(spec_string, module_set_name="default", explicit=True):
-        spec = spack.spec.Spec(spec_string).concretized()
+        spec = spack.concretize.concretize_one(spec_string)
         return writer_cls(spec, module_set_name, explicit), spec
 
     return _mock

lib/spack/spack/test/modules/lmod.py

@@ -8,6 +8,7 @@
 
 import archspec.cpu
 
+import spack.concretize
 import spack.config
 import spack.environment as ev
 import spack.main
@@ -435,7 +436,7 @@ def test_modules_relative_to_view(
             module_configuration("with_view")
             install("--add", "cmake")
 
-            spec = spack.spec.Spec("cmake").concretized()
+            spec = spack.concretize.concretize_one("cmake")
 
             content = modulefile_content("cmake")
             expected = e.default_view.get_projection_for_spec(spec)
@@ -455,7 +456,7 @@ def test_hide_implicits(self, module_configuration, temporary_store):
         """Tests the addition and removal of hide command in modulerc."""
         module_configuration("hide_implicits")
 
-        spec = spack.spec.Spec("mpileaks@2.3").concretized()
+        spec = spack.concretize.concretize_one("mpileaks@2.3")
 
         # mpileaks is defined as implicit, thus hide command should appear in modulerc
         writer = writer_cls(spec, "default", False)
@@ -507,8 +508,8 @@ def test_hide_implicits(self, module_configuration, temporary_store):
         # three versions of mpileaks are implicit
         writer = writer_cls(spec, "default", False)
         writer.write(overwrite=True)
-        spec_alt1 = spack.spec.Spec("mpileaks@2.2").concretized()
+        spec_alt1 = spack.concretize.concretize_one("mpileaks@2.2")
-        spec_alt2 = spack.spec.Spec("mpileaks@2.1").concretized()
+        spec_alt2 = spack.concretize.concretize_one("mpileaks@2.1")
         writer_alt1 = writer_cls(spec_alt1, "default", False)
         writer_alt1.write(overwrite=True)
         writer_alt2 = writer_cls(spec_alt2, "default", False)

lib/spack/spack/test/modules/tcl.py

@@ -8,9 +8,9 @@
 
 import archspec.cpu
 
+import spack.concretize
 import spack.modules.common
 import spack.modules.tcl
-import spack.spec
 
 mpich_spec_string = "mpich@3.0.4"
 mpileaks_spec_string = "mpileaks"
@@ -393,8 +393,7 @@ def test_setup_environment(self, modulefile_content, module_configuration):
         assert len([x for x in content if "setenv FOOBAR" in x]) == 1
         assert len([x for x in content if "setenv FOOBAR {mpileaks}" in x]) == 1
 
-        spec = spack.spec.Spec("mpileaks")
+        spec = spack.concretize.concretize_one("mpileaks")
-        spec.concretize()
         content = modulefile_content(spec["callpath"])
 
         assert len([x for x in content if "setenv FOOBAR" in x]) == 1
@@ -468,14 +467,12 @@ def test_hide_implicits_with_arg(self, module_configuration):
         module_configuration("exclude_implicits")
 
         # mpileaks is defined as explicit with explicit argument set on writer
-        mpileaks_spec = spack.spec.Spec("mpileaks")
+        mpileaks_spec = spack.concretize.concretize_one("mpileaks")
-        mpileaks_spec.concretize()
         writer = writer_cls(mpileaks_spec, "default", True)
         assert not writer.conf.excluded
 
         # callpath is defined as implicit with explicit argument set on writer
-        callpath_spec = spack.spec.Spec("callpath")
+        callpath_spec = spack.concretize.concretize_one("callpath")
-        callpath_spec.concretize()
         writer = writer_cls(callpath_spec, "default", False)
         assert writer.conf.excluded
 
@@ -510,7 +507,7 @@ def test_hide_implicits(self, module_configuration, temporary_store):
         """Tests the addition and removal of hide command in modulerc."""
         module_configuration("hide_implicits")
 
-        spec = spack.spec.Spec("mpileaks@2.3").concretized()
+        spec = spack.concretize.concretize_one("mpileaks@2.3")
 
         # mpileaks is defined as implicit, thus hide command should appear in modulerc
         writer = writer_cls(spec, "default", False)
@@ -557,8 +554,8 @@ def test_hide_implicits(self, module_configuration, temporary_store):
         # three versions of mpileaks are implicit
         writer = writer_cls(spec, "default", False)
         writer.write(overwrite=True)
-        spec_alt1 = spack.spec.Spec("mpileaks@2.2").concretized()
+        spec_alt1 = spack.concretize.concretize_one("mpileaks@2.2")
-        spec_alt2 = spack.spec.Spec("mpileaks@2.1").concretized()
+        spec_alt2 = spack.concretize.concretize_one("mpileaks@2.1")
         writer_alt1 = writer_cls(spec_alt1, "default", False)
         writer_alt1.write(overwrite=True)
         writer_alt2 = writer_cls(spec_alt2, "default", False)

lib/spack/spack/test/multimethod.py

@@ -6,9 +6,9 @@
 
 import pytest
 
+import spack.concretize
 import spack.config
 import spack.platforms
-import spack.spec
 from spack.multimethod import NoSuchMethodError
 
 pytestmark = [
@@ -28,7 +28,7 @@ def pkg_name(request):
 
 
 def test_no_version_match(pkg_name):
-    spec = spack.spec.Spec(pkg_name + "@2.0").concretized()
+    spec = spack.concretize.concretize_one(pkg_name + "@2.0")
     with pytest.raises(NoSuchMethodError):
         spec.package.no_version_2()
 
@@ -74,7 +74,7 @@ def test_multimethod_calls(
     with spack.config.override(
         "compilers", [compiler_factory(spec="apple-clang@9.1.0", operating_system="elcapitan")]
     ):
-        s = spack.spec.Spec(pkg_name + constraint_str).concretized()
+        s = spack.concretize.concretize_one(pkg_name + constraint_str)
     msg = f"Method {method_name} from {s} is giving a wrong result"
     assert getattr(s.package, method_name)() == expected_result, msg
 
@@ -83,10 +83,10 @@ def test_target_match(pkg_name):
     platform = spack.platforms.host()
     targets = list(platform.targets.values())
     for target in targets[:-1]:
-        s = spack.spec.Spec(pkg_name + " target=" + target.name).concretized()
+        s = spack.concretize.concretize_one(pkg_name + " target=" + target.name)
         assert s.package.different_by_target() == target.name
 
-    s = spack.spec.Spec(pkg_name + " target=" + targets[-1].name).concretized()
+    s = spack.concretize.concretize_one(pkg_name + " target=" + targets[-1].name)
     if len(targets) == 1:
         assert s.package.different_by_target() == targets[-1].name
     else:
@@ -116,5 +116,5 @@ def test_target_match(pkg_name):
     ],
 )
 def test_multimethod_calls_and_inheritance(spec_str, method_name, expected_result):
-    s = spack.spec.Spec(spec_str).concretized()
+    s = spack.concretize.concretize_one(spec_str)
     assert getattr(s.package, method_name)() == expected_result

lib/spack/spack/test/optional_deps.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+import spack.concretize
 from spack.spec import Spec
 
 
@@ -72,14 +73,11 @@ def spec_and_expected(request):
 
 
 def test_default_variant(config, mock_packages):
-    spec = Spec("optional-dep-test-3")
+    spec = spack.concretize.concretize_one("optional-dep-test-3")
-    spec.concretize()
     assert "pkg-a" in spec
 
-    spec = Spec("optional-dep-test-3~var")
+    spec = spack.concretize.concretize_one("optional-dep-test-3~var")
-    spec.concretize()
     assert "pkg-a" in spec
 
-    spec = Spec("optional-dep-test-3+var")
+    spec = spack.concretize.concretize_one("optional-dep-test-3+var")
-    spec.concretize()
     assert "pkg-b" in spec

lib/spack/spack/test/package_class.py

@@ -17,6 +17,7 @@
 import llnl.util.filesystem as fs
 
 import spack.compilers
+import spack.concretize
 import spack.deptypes as dt
 import spack.error
 import spack.install_test
@@ -166,8 +167,7 @@ def setup_install_test(source_paths, test_root):
 )
 def test_cache_extra_sources(install_mockery, spec, sources, extras, expect):
     """Test the package's cache extra test sources helper function."""
-    s = spack.spec.Spec(spec).concretized()
+    s = spack.concretize.concretize_one(spec)
-    s.package.spec.concretize()
 
     source_path = s.package.stage.source_path
     srcs = [fs.join_path(source_path, src) for src in sources]
@@ -205,8 +205,7 @@ def test_cache_extra_sources(install_mockery, spec, sources, extras, expect):
 
 
 def test_cache_extra_sources_fails(install_mockery):
-    s = spack.spec.Spec("pkg-a").concretized()
+    s = spack.concretize.concretize_one("pkg-a")
-    s.package.spec.concretize()
 
     with pytest.raises(InstallError) as exc_info:
         spack.install_test.cache_extra_test_sources(s.package, ["/a/b", "no-such-file"])

lib/spack/spack/test/packages.py

@@ -7,6 +7,7 @@
 import pytest
 
 import spack.build_systems.cmake as cmake
+import spack.concretize
 import spack.directives
 import spack.error
 import spack.fetch_strategy
@@ -75,13 +76,13 @@ def test_inheritance_of_directives(self):
         assert len(pkg_cls.provided) == 2
 
         # Check that Spec instantiation behaves as we expect
-        s = Spec("simple-inheritance").concretized()
+        s = spack.concretize.concretize_one("simple-inheritance")
         assert "^cmake" in s
         assert "^openblas" in s
         assert "+openblas" in s
         assert "mpi" in s
 
-        s = Spec("simple-inheritance~openblas").concretized()
+        s = spack.concretize.concretize_one("simple-inheritance~openblas")
         assert "^cmake" in s
         assert "^openblas" not in s
         assert "~openblas" in s
@@ -89,9 +90,8 @@ def test_inheritance_of_directives(self):
 
     @pytest.mark.regression("11844")
     def test_inheritance_of_patches(self):
-        s = Spec("patch-inheritance")
         # Will error if inheritor package cannot find inherited patch files
-        s.concretize()
+        _ = spack.concretize.concretize_one("patch-inheritance")
 
     def test_import_class_from_package(self):
         from spack.pkg.builtin.mock.mpich import Mpich  # noqa: F401
@@ -115,7 +115,7 @@ def test_import_namespace_container_modules(self):
 def test_urls_for_versions(mock_packages, config):
     """Version directive without a 'url' argument should use default url."""
     for spec_str in ("url_override@0.9.0", "url_override@1.0.0"):
-        s = Spec(spec_str).concretized()
+        s = spack.concretize.concretize_one(spec_str)
         url = s.package.url_for_version("0.9.0")
         assert url == "http://www.anothersite.org/uo-0.9.0.tgz"
 
@@ -137,7 +137,7 @@ def test_url_for_version_with_no_urls(mock_packages, config):
 
 
 def test_custom_cmake_prefix_path(mock_packages, config):
-    spec = Spec("depends-on-define-cmake-prefix-paths").concretized()
+    spec = spack.concretize.concretize_one("depends-on-define-cmake-prefix-paths")
 
     assert cmake.get_cmake_prefix_path(spec.package) == [
         spec["define-cmake-prefix-paths"].prefix.test
@@ -145,7 +145,7 @@ def test_custom_cmake_prefix_path(mock_packages, config):
 
 
 def test_url_for_version_with_only_overrides(mock_packages, config):
-    s = Spec("url-only-override").concretized()
+    s = spack.concretize.concretize_one("url-only-override")
 
     # these exist and should just take the URL provided in the package
     assert s.package.url_for_version("1.0.0") == "http://a.example.com/url_override-1.0.0.tar.gz"
@@ -160,7 +160,7 @@ def test_url_for_version_with_only_overrides(mock_packages, config):
 
 
 def test_url_for_version_with_only_overrides_with_gaps(mock_packages, config):
-    s = Spec("url-only-override-with-gaps").concretized()
+    s = spack.concretize.concretize_one("url-only-override-with-gaps")
 
     # same as for url-only-override -- these are specific
     assert s.package.url_for_version("1.0.0") == "http://a.example.com/url_override-1.0.0.tar.gz"

lib/spack/spack/test/packaging.py

@@ -20,6 +20,7 @@
 
 import spack.binary_distribution as bindist
 import spack.cmd.buildcache as buildcache
+import spack.concretize
 import spack.config
 import spack.error
 import spack.fetch_strategy
@@ -32,7 +33,6 @@
 from spack.installer import PackageInstaller
 from spack.paths import mock_gpg_keys_path
 from spack.relocate import macho_find_paths, relocate_links, relocate_text
-from spack.spec import Spec
 
 pytestmark = pytest.mark.not_on_windows("does not run on windows")
 
@@ -40,7 +40,7 @@
 @pytest.mark.usefixtures("install_mockery", "mock_gnupghome")
 def test_buildcache(mock_archive, tmp_path, monkeypatch, mutable_config):
     # Install a test package
-    spec = Spec("trivial-install-test-package").concretized()
+    spec = spack.concretize.concretize_one("trivial-install-test-package")
     monkeypatch.setattr(spec.package, "fetcher", URLFetchStrategy(url=mock_archive.url))
     PackageInstaller([spec.package], explicit=True).install()
     pkghash = "/" + str(spec.dag_hash(7))

lib/spack/spack/test/patch.py

@@ -12,6 +12,7 @@
 
 from llnl.util.filesystem import mkdirp, touch, working_dir
 
+import spack.concretize
 import spack.error
 import spack.fetch_strategy
 import spack.patch
@@ -91,7 +92,7 @@ def mock_patch_stage(tmpdir_factory, monkeypatch):
 def test_url_patch(mock_patch_stage, filename, sha256, archive_sha256, config):
     # Make a patch object
     url = url_util.path_to_file_url(filename)
-    s = Spec("patch").concretized()
+    s = spack.concretize.concretize_one("patch")
 
     # make a stage
     with Stage(url) as stage:  # TODO: url isn't used; maybe refactor Stage
@@ -145,8 +146,7 @@ def test_url_patch(mock_patch_stage, filename, sha256, archive_sha256, config):
 
 def test_patch_in_spec(mock_packages, config):
     """Test whether patches in a package appear in the spec."""
-    spec = Spec("patch")
+    spec = spack.concretize.concretize_one("patch")
-    spec.concretize()
     assert "patches" in list(spec.variants.keys())
 
     # Here the order is bar, foo, baz. Note that MV variants order
@@ -164,18 +164,15 @@ def test_patch_mixed_versions_subset_constraint(mock_packages, config):
     a patch applied to a version range of x.y.z versions is not applied to
     an x.y version.
     """
-    spec1 = Spec("patch@1.0.1")
+    spec1 = spack.concretize.concretize_one("patch@1.0.1")
-    spec1.concretize()
     assert biz_sha256 in spec1.variants["patches"].value
 
-    spec2 = Spec("patch@=1.0")
+    spec2 = spack.concretize.concretize_one("patch@=1.0")
-    spec2.concretize()
     assert biz_sha256 not in spec2.variants["patches"].value
 
 
 def test_patch_order(mock_packages, config):
-    spec = Spec("dep-diamond-patch-top")
+    spec = spack.concretize.concretize_one("dep-diamond-patch-top")
-    spec.concretize()
 
     mid2_sha256 = (
         "mid21234abcd1234abcd1234abcd1234abcd1234abcd1234abcd1234abcd1234"
@@ -233,8 +230,7 @@ def test_nested_directives(mock_packages):
 @pytest.mark.not_on_windows("Test requires Autotools")
 def test_patched_dependency(mock_packages, install_mockery, mock_fetch):
     """Test whether patched dependencies work."""
-    spec = Spec("patch-a-dependency")
+    spec = spack.concretize.concretize_one("patch-a-dependency")
-    spec.concretize()
     assert "patches" in list(spec["libelf"].variants.keys())
 
     # make sure the patch makes it into the dependency spec
@@ -274,8 +270,7 @@ def test_patch_failure_develop_spec_exits_gracefully(
 ):
     """ensure that a failing patch does not trigger exceptions for develop specs"""
 
-    spec = Spec(f"patch-a-dependency ^libelf dev_path={tmpdir}")
+    spec = spack.concretize.concretize_one(f"patch-a-dependency ^libelf dev_path={tmpdir}")
-    spec.concretize()
     libelf = spec["libelf"]
     assert "patches" in list(libelf.variants.keys())
     pkg = libelf.package
@@ -291,8 +286,7 @@ def test_patch_failure_restages(mock_packages, install_mockery, mock_fetch):
     ensure that a failing patch does not trigger exceptions
     for non-develop specs and the source gets restaged
     """
-    spec = Spec("patch-a-dependency")
+    spec = spack.concretize.concretize_one("patch-a-dependency")
-    spec.concretize()
     pkg = spec["libelf"].package
     with pkg.stage:
         bad_patch_indicator = trigger_bad_patch(pkg)
@@ -303,8 +297,7 @@ def test_patch_failure_restages(mock_packages, install_mockery, mock_fetch):
 
 def test_multiple_patched_dependencies(mock_packages, config):
     """Test whether multiple patched dependencies work."""
-    spec = Spec("patch-several-dependencies")
+    spec = spack.concretize.concretize_one("patch-several-dependencies")
-    spec.concretize()
 
     # basic patch on libelf
     assert "patches" in list(spec["libelf"].variants.keys())
@@ -319,8 +312,7 @@ def test_multiple_patched_dependencies(mock_packages, config):
 
 def test_conditional_patched_dependencies(mock_packages, config):
     """Test whether conditional patched dependencies work."""
-    spec = Spec("patch-several-dependencies @1.0")
+    spec = spack.concretize.concretize_one("patch-several-dependencies @1.0")
-    spec.concretize()
 
     # basic patch on libelf
     assert "patches" in list(spec["libelf"].variants.keys())
@@ -396,8 +388,9 @@ def get_patch(spec, ending):
 
 def test_conditional_patched_deps_with_conditions(mock_packages, config):
     """Test whether conditional patched dependencies with conditions work."""
-    spec = Spec("patch-several-dependencies @1.0 ^libdwarf@20111030")
+    spec = spack.concretize.concretize_one(
-    spec.concretize()
+        Spec("patch-several-dependencies @1.0 ^libdwarf@20111030")
+    )
 
     libelf = spec["libelf"]
     libdwarf = spec["libdwarf"]
@@ -412,8 +405,9 @@ def test_write_and_read_sub_dags_with_patched_deps(mock_packages, config):
     """Test whether patched dependencies are still correct after writing and
     reading a sub-DAG of a concretized Spec.
     """
-    spec = Spec("patch-several-dependencies @1.0 ^libdwarf@20111030")
+    spec = spack.concretize.concretize_one(
-    spec.concretize()
+        Spec("patch-several-dependencies @1.0 ^libdwarf@20111030")
+    )
 
     # write to YAML and read back in -- new specs will *only* contain
     # their sub-DAGs, and won't contain the dependent that patched them
@@ -474,7 +468,7 @@ def test_equality():
 
 def test_sha256_setter(mock_patch_stage, config):
     path = os.path.join(data_path, "foo.patch")
-    s = Spec("patch").concretized()
+    s = spack.concretize.concretize_one("patch")
     patch = spack.patch.FilePatch(s.package, path, level=1, working_dir=".")
     patch.sha256 = "abc"
 

lib/spack/spack/test/rewiring.py

@@ -8,11 +8,11 @@
 
 import pytest
 
+import spack.concretize
 import spack.deptypes as dt
 import spack.rewiring
 import spack.store
 from spack.installer import PackageInstaller
-from spack.spec import Spec
 from spack.test.relocate import text_in_bin
 
 if sys.platform == "darwin":
@@ -37,8 +37,8 @@ def check_spliced_spec_prefixes(spliced_spec):
 @pytest.mark.parametrize("transitive", [True, False])
 def test_rewire_db(mock_fetch, install_mockery, transitive):
     """Tests basic rewiring without binary executables."""
-    spec = Spec("splice-t^splice-h~foo").concretized()
+    spec = spack.concretize.concretize_one("splice-t^splice-h~foo")
-    dep = Spec("splice-h+foo").concretized()
+    dep = spack.concretize.concretize_one("splice-h+foo")
     PackageInstaller([spec.package, dep.package], explicit=True).install()
     spliced_spec = spec.splice(dep, transitive=transitive)
     assert spec.dag_hash() != spliced_spec.dag_hash()
@@ -61,8 +61,8 @@ def test_rewire_db(mock_fetch, install_mockery, transitive):
 @pytest.mark.parametrize("transitive", [True, False])
 def test_rewire_bin(mock_fetch, install_mockery, transitive):
     """Tests basic rewiring with binary executables."""
-    spec = Spec("quux").concretized()
+    spec = spack.concretize.concretize_one("quux")
-    dep = Spec("garply cflags=-g").concretized()
+    dep = spack.concretize.concretize_one("garply cflags=-g")
     PackageInstaller([spec.package, dep.package], explicit=True).install()
     spliced_spec = spec.splice(dep, transitive=transitive)
 
@@ -90,8 +90,8 @@ def test_rewire_bin(mock_fetch, install_mockery, transitive):
 def test_rewire_writes_new_metadata(mock_fetch, install_mockery):
     """Tests that new metadata was written during a rewire.
     Accuracy of metadata is left to other tests."""
-    spec = Spec("quux").concretized()
+    spec = spack.concretize.concretize_one("quux")
-    dep = Spec("garply cflags=-g").concretized()
+    dep = spack.concretize.concretize_one("garply cflags=-g")
     PackageInstaller([spec.package, dep.package], explicit=True).install()
     spliced_spec = spec.splice(dep, transitive=True)
     spack.rewiring.rewire(spliced_spec)
@@ -134,8 +134,8 @@ def test_rewire_writes_new_metadata(mock_fetch, install_mockery):
 @pytest.mark.parametrize("transitive", [True, False])
 def test_uninstall_rewired_spec(mock_fetch, install_mockery, transitive):
     """Test that rewired packages can be uninstalled as normal."""
-    spec = Spec("quux").concretized()
+    spec = spack.concretize.concretize_one("quux")
-    dep = Spec("garply cflags=-g").concretized()
+    dep = spack.concretize.concretize_one("garply cflags=-g")
     PackageInstaller([spec.package, dep.package], explicit=True).install()
     spliced_spec = spec.splice(dep, transitive=transitive)
     spack.rewiring.rewire(spliced_spec)
@@ -148,8 +148,8 @@ def test_uninstall_rewired_spec(mock_fetch, install_mockery, transitive):
 def test_rewire_not_installed_fails(mock_fetch, install_mockery):
     """Tests error when an attempt is made to rewire a package that was not
     previously installed."""
-    spec = Spec("quux").concretized()
+    spec = spack.concretize.concretize_one("quux")
-    dep = Spec("garply cflags=-g").concretized()
+    dep = spack.concretize.concretize_one("garply cflags=-g")
     spliced_spec = spec.splice(dep, False)
     with pytest.raises(
         spack.rewiring.PackageNotInstalledError,
@@ -163,8 +163,8 @@ def test_rewire_virtual(mock_fetch, install_mockery):
     dep = "splice-a"
     alt_dep = "splice-h"
 
-    spec = Spec(f"splice-vt^{dep}").concretized()
+    spec = spack.concretize.concretize_one(f"splice-vt^{dep}")
-    alt_spec = Spec(alt_dep).concretized()
+    alt_spec = spack.concretize.concretize_one(alt_dep)
 
     PackageInstaller([spec.package, alt_spec.package]).install()
 

lib/spack/spack/test/spec_dag.py

@@ -6,6 +6,7 @@
 """
 import pytest
 
+import spack.concretize
 import spack.deptypes as dt
 import spack.error
 import spack.repo
@@ -74,7 +75,7 @@ def test_test_deptype(tmpdir):
     builder.add_package("w", dependencies=[("x", "test", None), ("y", None, None)])
 
     with spack.repo.use_repositories(builder.root):
-        spec = Spec("w").concretized(tests=("w",))
+        spec = spack.concretize.concretize_one("w", tests=("w",))
         assert "x" in spec
         assert "z" not in spec
 
@@ -106,8 +107,7 @@ def test_installed_deps(monkeypatch, mock_packages):
     # BUT d is only a build dependency of C, so it won't constrain
     # link/run dependents of C when C is depended on as an existing
     # (concrete) installation.
-    c_spec = Spec(c)
+    c_spec = spack.concretize.concretize_one(c)
-    c_spec.concretize()
     assert c_spec[d].version == spack.version.Version("2")
 
     installed_names = [s.name for s in c_spec.traverse()]
@@ -122,7 +122,7 @@ def _mock_installed(self):
     # *if* we're doing a fresh installation.
     a_spec = Spec(a)
     a_spec._add_dependency(c_spec, depflag=dt.BUILD | dt.LINK, virtuals=())
-    a_spec.concretize()
+    a_spec = spack.concretize.concretize_one(a_spec)
     assert spack.version.Version("2") == a_spec[c][d].version
     assert spack.version.Version("2") == a_spec[e].version
     assert spack.version.Version("3") == a_spec[b][d].version
@@ -140,12 +140,12 @@ def test_specify_preinstalled_dep(tmpdir, monkeypatch):
     builder.add_package("pkg-a", dependencies=[("pkg-b", None, None)])
 
     with spack.repo.use_repositories(builder.root):
-        b_spec = Spec("pkg-b").concretized()
+        b_spec = spack.concretize.concretize_one("pkg-b")
         monkeypatch.setattr(Spec, "installed", property(lambda x: x.name != "pkg-a"))
 
         a_spec = Spec("pkg-a")
         a_spec._add_dependency(b_spec, depflag=dt.BUILD | dt.LINK, virtuals=())
-        a_spec.concretize()
+        a_spec = spack.concretize.concretize_one(a_spec)
 
         assert {x.name for x in a_spec.traverse()} == {"pkg-a", "pkg-b", "pkg-c"}
 
@@ -167,7 +167,7 @@ def test_conditional_dep_with_user_constraints(tmpdir, spec_str, expr_str, expec
     builder.add_package("x", dependencies=[("y", None, "x@2:")])
 
     with spack.repo.use_repositories(builder.root):
-        spec = Spec(spec_str).concretized()
+        spec = spack.concretize.concretize_one(spec_str)
         result = expr_str in spec
         assert result is expected, "{0} in {1}".format(expr_str, spec)
 
@@ -181,10 +181,10 @@ def test_conflicting_package_constraints(self, set_dependency):
         spec = Spec("mpileaks ^mpich ^callpath ^dyninst ^libelf ^libdwarf")
 
         with pytest.raises(spack.error.UnsatisfiableSpecError):
-            spec.concretize()
+            spack.concretize.concretize_one(spec)
 
     def test_preorder_node_traversal(self):
-        dag = Spec("mpileaks ^zmpi").concretized()
+        dag = spack.concretize.concretize_one("mpileaks ^zmpi")
 
         names = ["mpileaks", "callpath", "dyninst", "libdwarf", "libelf", "zmpi", "fake"]
         pairs = list(zip([0, 1, 2, 3, 4, 2, 3], names))
@@ -196,7 +196,7 @@ def test_preorder_node_traversal(self):
         assert [(x, y.name) for x, y in traversal] == pairs
 
     def test_preorder_edge_traversal(self):
-        dag = Spec("mpileaks ^zmpi").concretized()
+        dag = spack.concretize.concretize_one("mpileaks ^zmpi")
 
         names = [
             "mpileaks",
@@ -218,7 +218,7 @@ def test_preorder_edge_traversal(self):
         assert [(x, y.name) for x, y in traversal] == pairs
 
     def test_preorder_path_traversal(self):
-        dag = Spec("mpileaks ^zmpi").concretized()
+        dag = spack.concretize.concretize_one("mpileaks ^zmpi")
 
         names = [
             "mpileaks",
@@ -241,7 +241,7 @@ def test_preorder_path_traversal(self):
         assert [(x, y.name) for x, y in traversal] == pairs
 
     def test_postorder_node_traversal(self):
-        dag = Spec("mpileaks ^zmpi").concretized()
+        dag = spack.concretize.concretize_one("mpileaks ^zmpi")
 
         names = ["libelf", "libdwarf", "dyninst", "fake", "zmpi", "callpath", "mpileaks"]
         pairs = list(zip([4, 3, 2, 3, 2, 1, 0], names))
@@ -253,7 +253,7 @@ def test_postorder_node_traversal(self):
         assert [(x, y.name) for x, y in traversal] == pairs
 
     def test_postorder_edge_traversal(self):
-        dag = Spec("mpileaks ^zmpi").concretized()
+        dag = spack.concretize.concretize_one("mpileaks ^zmpi")
 
         names = [
             "libelf",
@@ -275,7 +275,7 @@ def test_postorder_edge_traversal(self):
         assert [(x, y.name) for x, y in traversal] == pairs
 
     def test_postorder_path_traversal(self):
-        dag = Spec("mpileaks ^zmpi").concretized()
+        dag = spack.concretize.concretize_one("mpileaks ^zmpi")
 
         names = [
             "libelf",
@@ -310,8 +310,8 @@ def test_dependents_and_dependencies_are_correct(self):
             }
         )
         check_links(spec)
-        spec.concretize()
+        concrete = spack.concretize.concretize_one(spec)
-        check_links(spec)
+        check_links(concrete)
 
     @pytest.mark.parametrize(
         "constraint_str,spec_str",
@@ -328,7 +328,7 @@ def test_unsatisfiable_cases(self, set_dependency, constraint_str, spec_str):
         """
         set_dependency("mpileaks", constraint_str)
         with pytest.raises(spack.error.UnsatisfiableSpecError):
-            Spec(spec_str).concretize()
+            spack.concretize.concretize_one(spec_str)
 
     @pytest.mark.parametrize(
         "spec_str", ["libelf ^mpich", "libelf ^libdwarf", "mpich ^dyninst ^libelf"]
@@ -336,7 +336,7 @@ def test_unsatisfiable_cases(self, set_dependency, constraint_str, spec_str):
     def test_invalid_dep(self, spec_str):
         spec = Spec(spec_str)
         with pytest.raises(spack.error.SpecError):
-            spec.concretize()
+            spack.concretize.concretize_one(spec)
 
     def test_equal(self):
         # Different spec structures to test for equality
@@ -398,8 +398,7 @@ def test_copy_simple(self):
         assert not orig_ids.intersection(copy_ids)
 
     def test_copy_concretized(self):
-        orig = Spec("mpileaks")
+        orig = spack.concretize.concretize_one("mpileaks")
-        orig.concretize()
         copy = orig.copy()
 
         check_links(copy)
@@ -417,7 +416,7 @@ def test_copy_through_spec_build_interface(self):
         """Check that copying dependencies using id(node) as a fast identifier of the
         node works when the spec is wrapped in a SpecBuildInterface object.
         """
-        s = Spec("mpileaks").concretized()
+        s = spack.concretize.concretize_one("mpileaks")
 
         c0 = s.copy()
         assert c0 == s
@@ -500,7 +499,7 @@ def test_copy_through_spec_build_interface(self):
         ],
     )
     def test_deptype_traversal(self, spec_str, deptypes, expected):
-        dag = Spec(spec_str).concretized()
+        dag = spack.concretize.concretize_one(spec_str)
         traversal = dag.traverse(deptype=deptypes)
         assert [x.name for x in traversal] == expected
 
@@ -620,20 +619,18 @@ def check_diamond_deptypes(self, spec):
 
     def test_concretize_deptypes(self):
         """Ensure that dependency types are preserved after concretization."""
-        s = Spec("dt-diamond")
+        s = spack.concretize.concretize_one("dt-diamond")
-        s.concretize()
         self.check_diamond_deptypes(s)
 
     def test_copy_deptypes(self):
         """Ensure that dependency types are preserved by spec copy."""
-        s1 = Spec("dt-diamond").concretized()
+        s1 = spack.concretize.concretize_one("dt-diamond")
         self.check_diamond_deptypes(s1)
         s2 = s1.copy()
         self.check_diamond_deptypes(s2)
 
     def test_getitem_query(self):
-        s = Spec("mpileaks")
+        s = spack.concretize.concretize_one("mpileaks")
-        s.concretize()
 
         # Check a query to a non-virtual package
         a = s["callpath"]
@@ -663,8 +660,7 @@ def test_getitem_query(self):
         assert query.isvirtual
 
     def test_getitem_exceptional_paths(self):
-        s = Spec("mpileaks")
+        s = spack.concretize.concretize_one("mpileaks")
-        s.concretize()
         # Needed to get a proxy object
         q = s["mpileaks"]
 
@@ -735,7 +731,7 @@ def test_invalid_literal_spec(self):
 
     def test_spec_tree_respect_deptypes(self):
         # Version-test-root uses version-test-pkg as a build dependency
-        s = Spec("version-test-root").concretized()
+        s = spack.concretize.concretize_one("version-test-root")
         out = s.tree(deptypes="all")
         assert "version-test-pkg" in out
         out = s.tree(deptypes=("link", "run"))
@@ -819,9 +815,9 @@ def test_synthetic_construction_of_split_dependencies_from_same_package(mock_pac
     #
     # To demonstrate that a spec can now hold two direct
     # dependencies from the same package
-    root = Spec("pkg-b").concretized()
+    root = spack.concretize.concretize_one("pkg-b")
-    link_run_spec = Spec("pkg-c@=1.0").concretized()
+    link_run_spec = spack.concretize.concretize_one("pkg-c@=1.0")
-    build_spec = Spec("pkg-c@=2.0").concretized()
+    build_spec = spack.concretize.concretize_one("pkg-c@=2.0")
 
     root.add_dependency_edge(link_run_spec, depflag=dt.LINK, virtuals=())
     root.add_dependency_edge(link_run_spec, depflag=dt.RUN, virtuals=())
@@ -848,8 +844,8 @@ def test_synthetic_construction_bootstrapping(mock_packages, config):
     #    | build
     #  pkg-b@1.0
     #
-    root = Spec("pkg-b@=2.0").concretized()
+    root = spack.concretize.concretize_one("pkg-b@=2.0")
-    bootstrap = Spec("pkg-b@=1.0").concretized()
+    bootstrap = spack.concretize.concretize_one("pkg-b@=1.0")
 
     root.add_dependency_edge(bootstrap, depflag=dt.BUILD, virtuals=())
 
@@ -866,8 +862,8 @@ def test_addition_of_different_deptypes_in_multiple_calls(mock_packages, config)
     #  pkg-b@1.0
     #
     # with three calls and check we always have a single edge
-    root = Spec("pkg-b@=2.0").concretized()
+    root = spack.concretize.concretize_one("pkg-b@=2.0")
-    bootstrap = Spec("pkg-b@=1.0").concretized()
+    bootstrap = spack.concretize.concretize_one("pkg-b@=1.0")
 
     for current_depflag in (dt.BUILD, dt.LINK, dt.RUN):
         root.add_dependency_edge(bootstrap, depflag=current_depflag, virtuals=())
@@ -894,9 +890,9 @@ def test_addition_of_different_deptypes_in_multiple_calls(mock_packages, config)
 def test_adding_same_deptype_with_the_same_name_raises(
     mock_packages, config, c1_depflag, c2_depflag
 ):
-    p = Spec("pkg-b@=2.0").concretized()
+    p = spack.concretize.concretize_one("pkg-b@=2.0")
-    c1 = Spec("pkg-b@=1.0").concretized()
+    c1 = spack.concretize.concretize_one("pkg-b@=1.0")
-    c2 = Spec("pkg-b@=2.0").concretized()
+    c2 = spack.concretize.concretize_one("pkg-b@=2.0")
 
     p.add_dependency_edge(c1, depflag=c1_depflag, virtuals=())
     with pytest.raises(spack.error.SpackError):

lib/spack/spack/test/spec_list.py

@@ -5,6 +5,7 @@
 
 import pytest
 
+import spack.concretize
 from spack.installer import PackageInstaller
 from spack.spec import Spec
 from spack.spec_list import SpecList
@@ -198,8 +199,8 @@ def test_spec_list_matrix_exclude(self, mock_packages):
 
     def test_spec_list_exclude_with_abstract_hashes(self, mock_packages, install_mockery):
         # Put mpich in the database so it can be referred to by hash.
-        mpich_1 = Spec("mpich+debug").concretized()
+        mpich_1 = spack.concretize.concretize_one("mpich+debug")
-        mpich_2 = Spec("mpich~debug").concretized()
+        mpich_2 = spack.concretize.concretize_one("mpich~debug")
         PackageInstaller([mpich_1.package, mpich_2.package], explicit=True, fake=True).install()
 
         # Create matrix and exclude +debug, which excludes the first mpich after its abstract hash

lib/spack/spack/test/spec_semantics.py

@@ -6,6 +6,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.deptypes as dt
 import spack.directives
 import spack.error
@@ -589,8 +590,7 @@ def test_satisfies_single_valued_variant(self):
         https://github.com/spack/spack/pull/2386#issuecomment-282147639
         is handled correctly.
         """
-        a = Spec("pkg-a foobar=bar")
+        a = spack.concretize.concretize_one("pkg-a foobar=bar")
-        a.concretize()
 
         assert a.satisfies("foobar=bar")
         assert a.satisfies("foobar=*")
@@ -609,21 +609,18 @@ def test_satisfies_single_valued_variant(self):
         assert "^pkg-b" in a
 
     def test_unsatisfied_single_valued_variant(self):
-        a = Spec("pkg-a foobar=baz")
+        a = spack.concretize.concretize_one("pkg-a foobar=baz")
-        a.concretize()
         assert "^pkg-b" not in a
 
-        mv = Spec("multivalue-variant")
+        mv = spack.concretize.concretize_one("multivalue-variant")
-        mv.concretize()
         assert "pkg-a@1.0" not in mv
 
     def test_indirect_unsatisfied_single_valued_variant(self):
-        spec = Spec("singlevalue-variant-dependent")
+        spec = spack.concretize.concretize_one("singlevalue-variant-dependent")
-        spec.concretize()
         assert "pkg-a@1.0" not in spec
 
     def test_satisfied_namespace(self):
-        spec = Spec("zlib").concretized()
+        spec = spack.concretize.concretize_one("zlib")
         assert spec.satisfies("namespace=builtin.mock")
         assert not spec.satisfies("namespace=builtin")
 
@@ -683,7 +680,7 @@ def test_unsatisfiable_multi_value_variant(self, default_mock_concretization):
         # ...but will fail during concretization if there are
         # values in the variant that are not allowed
         with pytest.raises(InvalidVariantValueError):
-            a.concretize()
+            spack.concretize.concretize_one(a)
 
         # This time we'll try to set a single-valued variant
         a = Spec('multivalue-variant fee="bar"')
@@ -700,11 +697,10 @@ def test_unsatisfiable_multi_value_variant(self, default_mock_concretization):
         # ...but will fail during concretization if there are
         # multiple values set
         with pytest.raises(MultipleValuesInExclusiveVariantError):
-            a.concretize()
+            spack.concretize.concretize_one(a)
 
     def test_copy_satisfies_transitive(self):
-        spec = Spec("dttop")
+        spec = spack.concretize.concretize_one("dttop")
-        spec.concretize()
         copy = spec.copy()
         for s in spec.traverse():
             assert s.satisfies(copy[s.name])
@@ -727,7 +723,7 @@ def test_intersects_virtual_providers(self):
 
     def test_intersectable_concrete_specs_must_have_the_same_hash(self):
         """Ensure that concrete specs are matched *exactly* by hash."""
-        s1 = Spec("mpileaks").concretized()
+        s1 = spack.concretize.concretize_one("mpileaks")
         s2 = s1.copy()
 
         assert s1.satisfies(s2)
@@ -767,17 +763,10 @@ def test_dep_index(self, default_mock_concretization):
 
     @pytest.mark.usefixtures("config")
     def test_virtual_index(self):
-        s = Spec("callpath")
+        s = spack.concretize.concretize_one("callpath")
-        s.concretize()
+        s_mpich = spack.concretize.concretize_one("callpath ^mpich")
-
+        s_mpich2 = spack.concretize.concretize_one("callpath ^mpich2")
-        s_mpich = Spec("callpath ^mpich")
+        s_zmpi = spack.concretize.concretize_one("callpath ^zmpi")
-        s_mpich.concretize()
-
-        s_mpich2 = Spec("callpath ^mpich2")
-        s_mpich2.concretize()
-
-        s_zmpi = Spec("callpath ^zmpi")
-        s_zmpi.concretize()
 
         assert s["mpi"].name != "mpi"
         assert s_mpich["mpi"].name == "mpich"
@@ -1047,7 +1036,7 @@ def test_abstract_spec_prefix_error(self):
             spec.prefix
 
     def test_forwarding_of_architecture_attributes(self):
-        spec = Spec("libelf target=x86_64").concretized()
+        spec = spack.concretize.concretize_one("libelf target=x86_64")
 
         # Check that we can still access each member through
         # the architecture attribute
@@ -1372,7 +1361,7 @@ def test_target_constraints(self, spec, constraint, expected_result):
     def test_error_message_unknown_variant(self):
         s = Spec("mpileaks +unknown")
         with pytest.raises(UnknownVariantError):
-            s.concretize()
+            spack.concretize.concretize_one(s)
 
     @pytest.mark.regression("18527")
     def test_satisfies_dependencies_ordered(self):
@@ -1399,8 +1388,7 @@ def test_splice_swap_names_mismatch_virtuals(self, default_mock_concretization,
     def test_spec_override(self):
         init_spec = Spec("pkg-a foo=baz foobar=baz cflags=-O3 cxxflags=-O1")
         change_spec = Spec("pkg-a foo=fee cflags=-O2")
-        new_spec = Spec.override(init_spec, change_spec)
+        new_spec = spack.concretize.concretize_one(Spec.override(init_spec, change_spec))
-        new_spec.concretize()
         assert "foo=fee" in new_spec
         # This check fails without concretizing: apparently if both specs are
         # abstract, then the spec will always be considered to satisfy
@@ -1419,8 +1407,7 @@ def test_spec_override_with_nonexisting_variant(self):
     def test_spec_override_with_variant_not_in_init_spec(self):
         init_spec = Spec("pkg-a foo=baz foobar=baz cflags=-O3 cxxflags=-O1")
         change_spec = Spec("pkg-a +bvv ~lorem_ipsum")
-        new_spec = Spec.override(init_spec, change_spec)
+        new_spec = spack.concretize.concretize_one(Spec.override(init_spec, change_spec))
-        new_spec.concretize()
         assert "+bvv" in new_spec
         assert "~lorem_ipsum" in new_spec
 
@@ -1513,7 +1500,7 @@ def test_virtual_deps_bindings(self, default_mock_concretization, spec_str, spec
     )
     def test_unsatisfiable_virtual_deps_bindings(self, spec_str):
         with pytest.raises(spack.solver.asp.UnsatisfiableSpecError):
-            Spec(spec_str).concretized()
+            spack.concretize.concretize_one(spec_str)
 
 
 @pytest.mark.parametrize(
@@ -1611,7 +1598,7 @@ def test_spec_format_path_posix(spec_str, format_str, expected, mock_git_test_pa
 def test_is_extension_after_round_trip_to_dict(config, mock_packages, spec_str):
     # x is constructed directly from string, y from a
     # round-trip to dict representation
-    x = Spec(spec_str).concretized()
+    x = spack.concretize.concretize_one(spec_str)
     y = Spec.from_dict(x.to_dict())
 
     # Using 'y' since the round-trip make us lose build dependencies
@@ -1712,7 +1699,7 @@ def test_call_dag_hash_on_old_dag_hash_spec(mock_packages, default_mock_concreti
 
 
 def test_spec_trim(mock_packages, config):
-    top = Spec("dt-diamond").concretized()
+    top = spack.concretize.concretize_one("dt-diamond")
     top.trim("dt-diamond-left")
     remaining = set(x.name for x in top.traverse())
     assert set(["dt-diamond", "dt-diamond-right", "dt-diamond-bottom"]) == remaining
@@ -1725,7 +1712,7 @@ def test_spec_trim(mock_packages, config):
 @pytest.mark.regression("30861")
 def test_concretize_partial_old_dag_hash_spec(mock_packages, config):
     # create an "old" spec with no package hash
-    bottom = Spec("dt-diamond-bottom").concretized()
+    bottom = spack.concretize.concretize_one("dt-diamond-bottom")
     delattr(bottom, "_package_hash")
 
     dummy_hash = "zd4m26eis2wwbvtyfiliar27wkcv3ehk"
@@ -1736,7 +1723,7 @@ def test_concretize_partial_old_dag_hash_spec(mock_packages, config):
     top.add_dependency_edge(bottom, depflag=0, virtuals=())
 
     # concretize with the already-concrete dependency
-    top.concretize()
+    top = spack.concretize.concretize_one(top)
 
     for spec in top.traverse():
         assert spec.concrete
@@ -1954,7 +1941,7 @@ def test_edge_equality_does_not_depend_on_virtual_order():
 
 
 def test_old_format_strings_trigger_error(default_mock_concretization):
-    s = Spec("pkg-a").concretized()
+    s = spack.concretize.concretize_one("pkg-a")
     with pytest.raises(SpecFormatStringError):
         s.format("${PACKAGE}-${VERSION}-${HASH}")
 

lib/spack/spack/test/spec_syntax.py

@@ -10,6 +10,7 @@
 
 import spack.binary_distribution
 import spack.cmd
+import spack.concretize
 import spack.platforms.test
 import spack.repo
 import spack.spec
@@ -776,7 +777,7 @@ def test_spec_by_hash_tokens(text, tokens):
 @pytest.mark.db
 def test_spec_by_hash(database, monkeypatch, config):
     mpileaks = database.query_one("mpileaks ^zmpi")
-    b = spack.spec.Spec("pkg-b").concretized()
+    b = spack.concretize.concretize_one("pkg-b")
     monkeypatch.setattr(spack.binary_distribution, "update_cache_and_get_specs", lambda: [b])
 
     hash_str = f"/{mpileaks.dag_hash()}"
@@ -873,7 +874,7 @@ def test_ambiguous_hash(mutable_database):
     In the past this ambiguity error would happen during parse time."""
 
     # This is a very sketchy as manually setting hashes easily breaks invariants
-    x1 = spack.spec.Spec("pkg-a").concretized()
+    x1 = spack.concretize.concretize_one("pkg-a")
     x2 = x1.copy()
     x1._hash = "xyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy"
     x1._process_hash = "xyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy"
@@ -947,8 +948,8 @@ def test_nonexistent_hash(database, config):
     ],
 )
 def test_disambiguate_hash_by_spec(spec1, spec2, constraint, mock_packages, monkeypatch, config):
-    spec1_concrete = spack.spec.Spec(spec1).concretized()
+    spec1_concrete = spack.concretize.concretize_one(spec1)
-    spec2_concrete = spack.spec.Spec(spec2).concretized()
+    spec2_concrete = spack.concretize.concretize_one(spec2)
 
     spec1_concrete._hash = "spec1"
     spec2_concrete._hash = "spec2"
@@ -1139,7 +1140,7 @@ def test_parse_filename_missing_slash_as_spec(specfile_for, tmpdir, filename):
     # Check that if we concretize this spec, we get a good error
     # message that mentions we might've meant a file.
     with pytest.raises(spack.repo.UnknownEntityError) as exc_info:
-        spec.concretize()
+        spack.concretize.concretize_one(spec)
     assert exc_info.value.long_message
     assert (
         "Did you mean to specify a filename with './libelf.yaml'?" in exc_info.value.long_message
@@ -1147,7 +1148,7 @@ def test_parse_filename_missing_slash_as_spec(specfile_for, tmpdir, filename):
 
     # make sure that only happens when the spec ends in yaml
     with pytest.raises(spack.repo.UnknownPackageError) as exc_info:
-        SpecParser("builtin.mock.doesnotexist").next_spec().concretize()
+        spack.concretize.concretize_one(SpecParser("builtin.mock.doesnotexist").next_spec())
     assert not exc_info.value.long_message or (
         "Did you mean to specify a filename with" not in exc_info.value.long_message
     )

lib/spack/spack/test/spec_yaml.py

@@ -20,6 +20,7 @@
 import pytest
 import ruamel.yaml
 
+import spack.concretize
 import spack.hash_types as ht
 import spack.paths
 import spack.repo
@@ -107,8 +108,7 @@ def test_roundtrip_concrete_specs(abstract_spec, default_mock_concretization):
 
 
 def test_yaml_subdag(config, mock_packages):
-    spec = Spec("mpileaks^mpich+debug")
+    spec = spack.concretize.concretize_one("mpileaks^mpich+debug")
-    spec.concretize()
     yaml_spec = Spec.from_yaml(spec.to_yaml())
     json_spec = Spec.from_json(spec.to_json())
 
@@ -153,8 +153,7 @@ def test_ordered_read_not_required_for_consistent_dag_hash(config, mock_packages
     """
     specs = ["mpileaks ^zmpi", "dttop", "dtuse"]
     for spec in specs:
-        spec = Spec(spec)
+        spec = spack.concretize.concretize_one(spec)
-        spec.concretize()
 
         #
         # Dict & corresponding YAML & JSON from the original spec.
@@ -214,11 +213,15 @@ def test_ordered_read_not_required_for_consistent_dag_hash(config, mock_packages
         assert spec.dag_hash() == round_trip_reversed_json_spec.dag_hash()
 
         # dag_hash is equal after round-trip by dag_hash
-        spec.concretize()
+        spec = spack.concretize.concretize_one(spec)
-        round_trip_yaml_spec.concretize()
+        round_trip_yaml_spec = spack.concretize.concretize_one(round_trip_yaml_spec)
-        round_trip_json_spec.concretize()
+        round_trip_json_spec = spack.concretize.concretize_one(round_trip_json_spec)
-        round_trip_reversed_yaml_spec.concretize()
+        round_trip_reversed_yaml_spec = spack.concretize.concretize_one(
-        round_trip_reversed_json_spec.concretize()
+            round_trip_reversed_yaml_spec
+        )
+        round_trip_reversed_json_spec = spack.concretize.concretize_one(
+            round_trip_reversed_json_spec
+        )
         assert spec.dag_hash() == round_trip_yaml_spec.dag_hash()
         assert spec.dag_hash() == round_trip_json_spec.dag_hash()
         assert spec.dag_hash() == round_trip_reversed_yaml_spec.dag_hash()
@@ -322,7 +325,7 @@ def test_save_dependency_spec_jsons_subset(tmpdir, config):
     builder.add_package("pkg-a", dependencies=[("pkg-b", None, None), ("pkg-c", None, None)])
 
     with spack.repo.use_repositories(builder.root):
-        spec_a = Spec("pkg-a").concretized()
+        spec_a = spack.concretize.concretize_one("pkg-a")
         b_spec = spec_a["pkg-b"]
         c_spec = spec_a["pkg-c"]
 
@@ -389,7 +392,7 @@ def test_legacy_yaml(tmpdir, install_mockery, mock_packages):
     build_hash: iaapywazxgetn6gfv2cfba353qzzqvhy
 """
     spec = Spec.from_yaml(yaml)
-    concrete_spec = spec.concretized()
+    concrete_spec = spack.concretize.concretize_one(spec)
     assert concrete_spec.eq_dag(spec)
 
 

lib/spack/spack/test/svn_fetch.py

@@ -8,9 +8,9 @@
 
 from llnl.util.filesystem import mkdirp, touch, working_dir
 
+import spack.concretize
 import spack.config
 from spack.fetch_strategy import SvnFetchStrategy
-from spack.spec import Spec
 from spack.stage import Stage
 from spack.util.executable import which
 from spack.version import Version
@@ -40,7 +40,7 @@ def test_fetch(type_of_test, secure, mock_svn_repository, config, mutable_mock_r
     h = mock_svn_repository.hash
 
     # Construct the package under test
-    s = Spec("svn-test").concretized()
+    s = spack.concretize.concretize_one("svn-test")
     monkeypatch.setitem(s.package.versions, Version("svn"), t.args)
 
     # Enter the stage directory and check some properties

lib/spack/spack/test/test_suite.py

@@ -9,6 +9,7 @@
 
 from llnl.util.filesystem import join_path, mkdirp, touch
 
+import spack.concretize
 import spack.config
 import spack.install_test
 import spack.spec
@@ -39,7 +40,7 @@ def ensure_results(filename, expected, present=True):
 
 def test_test_log_name(mock_packages, config):
     """Ensure test log path is reasonable."""
-    spec = spack.spec.Spec("libdwarf").concretized()
+    spec = spack.concretize.concretize_one("libdwarf")
 
     test_name = "test_name"
 
@@ -52,7 +53,7 @@ def test_test_log_name(mock_packages, config):
 
 def test_test_ensure_stage(mock_test_stage, mock_packages):
     """Make sure test stage directory is properly set up."""
-    spec = spack.spec.Spec("libdwarf").concretized()
+    spec = spack.concretize.concretize_one("libdwarf")
 
     test_name = "test_name"
 
@@ -65,7 +66,7 @@ def test_test_ensure_stage(mock_test_stage, mock_packages):
 
 def test_write_test_result(mock_packages, mock_test_stage):
     """Ensure test results written to a results file."""
-    spec = spack.spec.Spec("libdwarf").concretized()
+    spec = spack.concretize.concretize_one("libdwarf")
     result = "TEST"
     test_name = "write-test"
 
@@ -85,7 +86,7 @@ def test_write_test_result(mock_packages, mock_test_stage):
 
 def test_test_not_installed(mock_packages, install_mockery, mock_test_stage):
     """Attempt to perform stand-alone test for not_installed package."""
-    spec = spack.spec.Spec("trivial-smoke-test").concretized()
+    spec = spack.concretize.concretize_one("trivial-smoke-test")
     test_suite = spack.install_test.TestSuite([spec])
 
     test_suite()
@@ -102,7 +103,7 @@ def test_test_external(
     mock_packages, install_mockery, mock_test_stage, monkeypatch, arguments, status, msg
 ):
     name = "trivial-smoke-test"
-    spec = spack.spec.Spec(name).concretized()
+    spec = spack.concretize.concretize_one(name)
     spec.external_path = "/path/to/external/{0}".format(name)
 
     monkeypatch.setattr(spack.spec.Spec, "installed", _true)
@@ -123,7 +124,7 @@ def ensure_current_cache_fail(test_suite):
         with pytest.raises(spack.install_test.TestSuiteSpecError):
             _ = test_suite.current_test_data_dir
 
-    spec = spack.spec.Spec("libelf").concretized()
+    spec = spack.concretize.concretize_one("libelf")
     test_suite = spack.install_test.TestSuite([spec], "test-cache")
 
     # Check no current specs yield failure
@@ -141,7 +142,7 @@ def ensure_current_cache_fail(test_suite):
 
 
 def test_test_spec_run_once(mock_packages, install_mockery, mock_test_stage):
-    spec = spack.spec.Spec("libelf").concretized()
+    spec = spack.concretize.concretize_one("libelf")
     test_suite = spack.install_test.TestSuite([spec], "test-dups")
     (test_suite.specs[0]).package.test_suite = test_suite
 
@@ -151,7 +152,7 @@ def test_test_spec_run_once(mock_packages, install_mockery, mock_test_stage):
 
 @pytest.mark.not_on_windows("Cannot find echo executable")
 def test_test_spec_passes(mock_packages, install_mockery, mock_test_stage, monkeypatch):
-    spec = spack.spec.Spec("simple-standalone-test").concretized()
+    spec = spack.concretize.concretize_one("simple-standalone-test")
     monkeypatch.setattr(spack.spec.Spec, "installed", _true)
     test_suite = spack.install_test.TestSuite([spec])
     test_suite()
@@ -177,7 +178,7 @@ def test_get_test_suite_too_many(mock_packages, mock_test_stage):
     name = "duplicate-alias"
 
     def add_suite(package):
-        spec = spack.spec.Spec(package).concretized()
+        spec = spack.concretize.concretize_one(package)
         suite = spack.install_test.TestSuite([spec], name)
         suite.ensure_stage()
         spack.install_test.write_test_suite_file(suite)
@@ -199,7 +200,7 @@ def add_suite(package):
 )
 def test_test_function_names(mock_packages, install_mockery, virtuals, expected):
     """Confirm test_function_names works as expected with/without virtuals."""
-    spec = spack.spec.Spec("mpich").concretized()
+    spec = spack.concretize.concretize_one("mpich")
     tests = spack.install_test.test_function_names(spec.package, add_virtuals=virtuals)
     assert sorted(tests) == sorted(expected)
 
@@ -212,7 +213,7 @@ def test_test_functions_fails():
 
 def test_test_functions_pkgless(mock_packages, install_mockery, ensure_debug, capsys):
     """Confirm works for package providing a package-less virtual."""
-    spec = spack.spec.Spec("simple-standalone-test").concretized()
+    spec = spack.concretize.concretize_one("simple-standalone-test")
     fns = spack.install_test.test_functions(spec.package, add_virtuals=True)
     out = capsys.readouterr()
     assert len(fns) == 2, "Expected two test functions"
@@ -295,7 +296,7 @@ def test_process_test_parts(mock_packages):
 
 def test_test_part_fail(tmpdir, install_mockery, mock_fetch, mock_test_stage):
     """Confirm test_part with a ProcessError results in FAILED status."""
-    s = spack.spec.Spec("trivial-smoke-test").concretized()
+    s = spack.concretize.concretize_one("trivial-smoke-test")
     pkg = s.package
     pkg.tester.test_log_file = str(tmpdir.join("test-log.txt"))
     touch(pkg.tester.test_log_file)
@@ -311,7 +312,7 @@ def test_test_part_fail(tmpdir, install_mockery, mock_fetch, mock_test_stage):
 
 def test_test_part_pass(install_mockery, mock_fetch, mock_test_stage):
     """Confirm test_part that succeeds results in PASSED status."""
-    s = spack.spec.Spec("trivial-smoke-test").concretized()
+    s = spack.concretize.concretize_one("trivial-smoke-test")
     pkg = s.package
 
     name = "test_echo"
@@ -330,7 +331,7 @@ def test_test_part_pass(install_mockery, mock_fetch, mock_test_stage):
 
 def test_test_part_skip(install_mockery, mock_fetch, mock_test_stage):
     """Confirm test_part that raises SkipTest results in test status SKIPPED."""
-    s = spack.spec.Spec("trivial-smoke-test").concretized()
+    s = spack.concretize.concretize_one("trivial-smoke-test")
     pkg = s.package
 
     name = "test_skip"
@@ -344,7 +345,7 @@ def test_test_part_skip(install_mockery, mock_fetch, mock_test_stage):
 
 def test_test_part_missing_exe_fail_fast(tmpdir, install_mockery, mock_fetch, mock_test_stage):
     """Confirm test_part with fail fast enabled raises exception."""
-    s = spack.spec.Spec("trivial-smoke-test").concretized()
+    s = spack.concretize.concretize_one("trivial-smoke-test")
     pkg = s.package
     pkg.tester.test_log_file = str(tmpdir.join("test-log.txt"))
     touch(pkg.tester.test_log_file)
@@ -365,7 +366,7 @@ def test_test_part_missing_exe_fail_fast(tmpdir, install_mockery, mock_fetch, mo
 
 def test_test_part_missing_exe(tmpdir, install_mockery, mock_fetch, mock_test_stage):
     """Confirm test_part with missing executable fails."""
-    s = spack.spec.Spec("trivial-smoke-test").concretized()
+    s = spack.concretize.concretize_one("trivial-smoke-test")
     pkg = s.package
     pkg.tester.test_log_file = str(tmpdir.join("test-log.txt"))
     touch(pkg.tester.test_log_file)
@@ -401,7 +402,7 @@ def test_embedded_test_part_status(
 ):
     """Check to ensure the status of the enclosing test part reflects summary of embedded parts."""
 
-    s = spack.spec.Spec("trivial-smoke-test").concretized()
+    s = spack.concretize.concretize_one("trivial-smoke-test")
     pkg = s.package
     base_name = "test_example"
     part_name = f"{pkg.__class__.__name__}::{base_name}"
@@ -428,7 +429,7 @@ def test_write_tested_status(
     tmpdir, install_mockery, mock_fetch, mock_test_stage, statuses, expected
 ):
     """Check to ensure the status of the enclosing test part reflects summary of embedded parts."""
-    s = spack.spec.Spec("trivial-smoke-test").concretized()
+    s = spack.concretize.concretize_one("trivial-smoke-test")
     pkg = s.package
     for i, status in enumerate(statuses):
         pkg.tester.test_parts[f"test_{i}"] = status
@@ -444,7 +445,7 @@ def test_write_tested_status(
 @pytest.mark.regression("37840")
 def test_write_tested_status_no_repeats(tmpdir, install_mockery, mock_fetch, mock_test_stage):
     """Emulate re-running the same stand-alone tests a second time."""
-    s = spack.spec.Spec("trivial-smoke-test").concretized()
+    s = spack.concretize.concretize_one("trivial-smoke-test")
     pkg = s.package
     statuses = [TestStatus.PASSED, TestStatus.PASSED]
     for i, status in enumerate(statuses):

lib/spack/spack/test/url_fetch.py

@@ -13,6 +13,7 @@
 import llnl.util.tty as tty
 from llnl.util.filesystem import is_exe, working_dir
 
+import spack.concretize
 import spack.config
 import spack.error
 import spack.fetch_strategy as fs
@@ -21,7 +22,6 @@
 import spack.util.executable
 import spack.util.web as web_util
 import spack.version
-from spack.spec import Spec
 from spack.stage import Stage
 from spack.util.executable import which
 
@@ -192,7 +192,7 @@ def test_from_list_url(mock_packages, config, spec, url, digest, _fetch_method):
     have checksums in the package.
     """
     with spack.config.override("config:url_fetch_method", _fetch_method):
-        s = Spec(spec).concretized()
+        s = spack.concretize.concretize_one(spec)
         fetch_strategy = fs.from_list_url(s.package)
         assert isinstance(fetch_strategy, fs.URLFetchStrategy)
         assert os.path.basename(fetch_strategy.url) == url
@@ -218,7 +218,7 @@ def test_new_version_from_list_url(
 ):
     """Test non-specific URLs from the url-list-test package."""
     with spack.config.override("config:url_fetch_method", _fetch_method):
-        s = Spec(f"url-list-test @{requested_version}").concretized()
+        s = spack.concretize.concretize_one(f"url-list-test @{requested_version}")
         fetch_strategy = fs.from_list_url(s.package)
 
         assert isinstance(fetch_strategy, fs.URLFetchStrategy)
@@ -232,7 +232,7 @@ def test_new_version_from_list_url(
 
 def test_nosource_from_list_url(mock_packages, config):
     """This test confirms BundlePackages do not have list url."""
-    s = Spec("nosource").concretized()
+    s = spack.concretize.concretize_one("nosource")
     fetch_strategy = fs.from_list_url(s.package)
     assert fetch_strategy is None
 

lib/spack/spack/test/util/package_hash.py

@@ -7,6 +7,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.directives
 import spack.directives_meta
 import spack.paths
@@ -91,8 +92,8 @@ def test_all_same_but_install(mock_packages, config):
 
 
 def test_content_hash_all_same_but_patch_contents(mock_packages, config):
-    spec1 = Spec("hash-test1@1.1").concretized()
+    spec1 = spack.concretize.concretize_one("hash-test1@1.1")
-    spec2 = Spec("hash-test2@1.1").concretized()
+    spec2 = spack.concretize.concretize_one("hash-test2@1.1")
     compare_hash_sans_name(False, spec1, spec2)
 
 
@@ -117,8 +118,8 @@ def test_content_hash_not_concretized(mock_packages, config):
 
 
 def test_content_hash_different_variants(mock_packages, config):
-    spec1 = Spec("hash-test1@1.2 +variantx").concretized()
+    spec1 = spack.concretize.concretize_one("hash-test1@1.2 +variantx")
-    spec2 = Spec("hash-test2@1.2 ~variantx").concretized()
+    spec2 = spack.concretize.concretize_one("hash-test2@1.2 ~variantx")
     compare_hash_sans_name(True, spec1, spec2)
 
 
@@ -132,19 +133,19 @@ def test_content_hash_cannot_get_details_from_ast(mock_packages, config):
     differ where Spack includes a phase on account of AST-examination
     failure.
     """
-    spec3 = Spec("hash-test1@1.7").concretized()
+    spec3 = spack.concretize.concretize_one("hash-test1@1.7")
-    spec4 = Spec("hash-test3@1.7").concretized()
+    spec4 = spack.concretize.concretize_one("hash-test3@1.7")
     compare_hash_sans_name(False, spec3, spec4)
 
 
 def test_content_hash_all_same_but_archive_hash(mock_packages, config):
-    spec1 = Spec("hash-test1@1.3").concretized()
+    spec1 = spack.concretize.concretize_one("hash-test1@1.3")
-    spec2 = Spec("hash-test2@1.3").concretized()
+    spec2 = spack.concretize.concretize_one("hash-test2@1.3")
     compare_hash_sans_name(False, spec1, spec2)
 
 
 def test_content_hash_parse_dynamic_function_call(mock_packages, config):
-    spec = Spec("hash-test4").concretized()
+    spec = spack.concretize.concretize_one("hash-test4")
     spec.package.content_hash()
 
 

lib/spack/spack/test/variant.py

@@ -5,6 +5,7 @@
 
 import pytest
 
+import spack.concretize
 import spack.error
 import spack.repo
 import spack.spec
@@ -686,12 +687,11 @@ def test_str(self) -> None:
 
     def test_concrete(self, mock_packages, config) -> None:
         spec = Spec("pkg-a")
-        vm = VariantMap(spec)
+        assert not VariantMap(spec).concrete
-        assert not vm.concrete
 
         # concrete if associated spec is concrete
-        spec.concretize()
+        spec = spack.concretize.concretize_one(spec)
-        assert vm.concrete
+        assert VariantMap(spec).concrete
 
         # concrete if all variants are present (even if spec not concrete)
         spec._mark_concrete(False)
@@ -910,7 +910,7 @@ def test_concretize_variant_default_with_multiple_defs(
     pkg = spack.repo.PATH.get_pkg_class(pkg_name)
     pkg_defs = [vdef for _, vdef in pkg.variant_definitions("v")]
 
-    spec = spack.spec.Spec(f"{pkg_name}{spec}").concretized()
+    spec = spack.concretize.concretize_one(f"{pkg_name}{spec}")
     assert spec.satisfies(satisfies)
     assert spec.package.get_variant("v") is pkg_defs[def_id]
 

lib/spack/spack/test/versions.py

@@ -13,6 +13,7 @@
 
 from llnl.util.filesystem import working_dir
 
+import spack.concretize
 import spack.package_base
 import spack.spec
 import spack.version
@@ -707,7 +708,9 @@ def test_git_hash_comparisons(
         spack.package_base.PackageBase, "git", pathlib.Path(repo_path).as_uri(), raising=False
     )
 
-    spec = spack.spec.Spec(f"git-test-commit@{commits[commit_idx]}").concretized()
+    spec = spack.concretize.concretize_one(
+        spack.spec.Spec(f"git-test-commit@{commits[commit_idx]}")
+    )
     for item in expected_satisfies:
         assert spec.satisfies(item)
 
@@ -723,15 +726,13 @@ def test_git_ref_comparisons(mock_git_version_info, install_mockery, mock_packag
     )
 
     # Spec based on tag v1.0
-    spec_tag = spack.spec.Spec("git-test-commit@git.v1.0")
+    spec_tag = spack.concretize.concretize_one("git-test-commit@git.v1.0")
-    spec_tag.concretize()
     assert spec_tag.satisfies("@1.0")
     assert not spec_tag.satisfies("@1.1:")
     assert str(spec_tag.version) == "git.v1.0=1.0"
 
     # Spec based on branch 1.x
-    spec_branch = spack.spec.Spec("git-test-commit@git.1.x")
+    spec_branch = spack.concretize.concretize_one("git-test-commit@git.1.x")
-    spec_branch.concretize()
     assert spec_branch.satisfies("@1.2")
     assert spec_branch.satisfies("@1.1:1.3")
     assert str(spec_branch.version) == "git.1.x=1.2"
@@ -1030,7 +1031,7 @@ def test_git_version_repo_attached_after_serialization(
     monkeypatch.setattr(
         spack.package_base.PackageBase, "git", "file://%s" % repo_path, raising=False
     )
-    spec = spack.spec.Spec(f"git-test-commit@{commits[-2]}").concretized()
+    spec = spack.concretize.concretize_one(f"git-test-commit@{commits[-2]}")
 
     # Before serialization, the repo is attached
     assert spec.satisfies("@1.0")
@@ -1050,7 +1051,7 @@ def test_resolved_git_version_is_shown_in_str(
         spack.package_base.PackageBase, "git", "file://%s" % repo_path, raising=False
     )
     commit = commits[-3]
-    spec = spack.spec.Spec(f"git-test-commit@{commit}").concretized()
+    spec = spack.concretize.concretize_one(f"git-test-commit@{commit}")
 
     assert spec.version.satisfies(ver("1.0"))
     assert str(spec.version) == f"{commit}=1.0-git.1"

lib/spack/spack/test/views.py

@@ -6,6 +6,7 @@
 
 import pytest
 
+import spack.concretize
 from spack.directory_layout import DirectoryLayout
 from spack.filesystem_view import SimpleFilesystemView, YamlFilesystemView
 from spack.installer import PackageInstaller
@@ -16,7 +17,7 @@ def test_remove_extensions_ordered(install_mockery, mock_fetch, tmpdir):
     view_dir = str(tmpdir.join("view"))
     layout = DirectoryLayout(view_dir)
     view = YamlFilesystemView(view_dir, layout)
-    e2 = Spec("extension2").concretized()
+    e2 = spack.concretize.concretize_one("extension2")
     PackageInstaller([e2.package], explicit=True).install()
     view.add_specs(e2)