spec.py: further arch related fixes

.github/workflows/build-containers.yml

@@ -40,17 +40,17 @@ jobs:
         # 1: Platforms to build for
         # 2: Base image (e.g. ubuntu:22.04)
         dockerfile: [[amazon-linux, 'linux/amd64,linux/arm64', 'amazonlinux:2'],
-                     [centos-stream9, 'linux/amd64,linux/arm64', 'centos:stream9'],
-                     [leap15, 'linux/amd64,linux/arm64', 'opensuse/leap:15'],
-                     [ubuntu-focal, 'linux/amd64,linux/arm64', 'ubuntu:20.04'],
-                     [ubuntu-jammy, 'linux/amd64,linux/arm64', 'ubuntu:22.04'],
-                     [ubuntu-noble, 'linux/amd64,linux/arm64', 'ubuntu:24.04'],
-                     [almalinux8, 'linux/amd64,linux/arm64', 'almalinux:8'],
-                     [almalinux9, 'linux/amd64,linux/arm64', 'almalinux:9'],
+                     [centos-stream9, 'linux/amd64,linux/arm64,linux/ppc64le', 'centos:stream9'],
+                     [leap15, 'linux/amd64,linux/arm64,linux/ppc64le', 'opensuse/leap:15'],
+                     [ubuntu-focal, 'linux/amd64,linux/arm64,linux/ppc64le', 'ubuntu:20.04'],
+                     [ubuntu-jammy, 'linux/amd64,linux/arm64,linux/ppc64le', 'ubuntu:22.04'],
+                     [ubuntu-noble, 'linux/amd64,linux/arm64,linux/ppc64le', 'ubuntu:24.04'],
+                     [almalinux8, 'linux/amd64,linux/arm64,linux/ppc64le', 'almalinux:8'],
+                     [almalinux9, 'linux/amd64,linux/arm64,linux/ppc64le', 'almalinux:9'],
                      [rockylinux8, 'linux/amd64,linux/arm64', 'rockylinux:8'],
                      [rockylinux9, 'linux/amd64,linux/arm64', 'rockylinux:9'],
-                     [fedora39, 'linux/amd64,linux/arm64', 'fedora:39'],
-                     [fedora40, 'linux/amd64,linux/arm64', 'fedora:40']]
+                     [fedora39, 'linux/amd64,linux/arm64,linux/ppc64le', 'fedora:39'],
+                     [fedora40, 'linux/amd64,linux/arm64,linux/ppc64le', 'fedora:40']]
     name: Build ${{ matrix.dockerfile[0] }}
     if: github.repository == 'spack/spack'
     steps:

.github/workflows/ci.yaml

@@ -81,10 +81,6 @@ jobs:
     with:
       with_coverage: ${{ needs.changes.outputs.core }}
 
-  import-check:
-    needs: [ changes ]
-    uses: ./.github/workflows/import-check.yaml
-
   all-prechecks:
     needs: [ prechecks ]
     if: ${{ always() }}

.github/workflows/coverage.yml

@@ -33,4 +33,3 @@ jobs:
       with:
         verbose: true
         fail_ci_if_error: false
-        token: ${{ secrets.CODECOV_TOKEN }}

.github/workflows/import-check.yaml

@@ -1,49 +0,0 @@
-name: import-check
-
-on:
-  workflow_call:
-
-jobs:
-  # Check we don't make the situation with circular imports worse
-  import-check:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: julia-actions/setup-julia@v2
-      with:
-        version: '1.10'
-    - uses: julia-actions/cache@v2
-
-    # PR: use the base of the PR as the old commit
-    - name: Checkout PR base commit
-      if: github.event_name == 'pull_request'
-      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-      with:
-        ref: ${{ github.event.pull_request.base.sha }}
-        path: old
-    # not a PR: use the previous commit as the old commit
-    - name: Checkout previous commit
-      if: github.event_name != 'pull_request'
-      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-      with:
-        fetch-depth: 2
-        path: old
-    - name: Checkout previous commit
-      if: github.event_name != 'pull_request'
-      run: git -C old reset --hard HEAD^
-
-    - name: Checkout new commit
-      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-      with:
-        path: new
-    - name: Install circular import checker
-      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-      with:
-        repository: haampie/circular-import-fighter
-        ref: 4cdb0bf15f04ab6b49041d5ef1bfd9644cce7f33
-        path: circular-import-fighter
-    - name: Install dependencies
-      working-directory: circular-import-fighter
-      run: make -j dependencies
-    - name: Circular import check
-      working-directory: circular-import-fighter
-      run: make -j compare "SPACK_ROOT=../old ../new"

.github/workflows/valid-style.yml

@@ -86,6 +86,66 @@ jobs:
           spack -d bootstrap now --dev
           spack -d style -t black
           spack unit-test -V
+  # Check we don't make the situation with circular imports worse
+  import-check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: julia-actions/setup-julia@v2
+      with:
+        version: '1.10'
+    - uses: julia-actions/cache@v2
+
+    # PR: use the base of the PR as the old commit
+    - name: Checkout PR base commit
+      if: github.event_name == 'pull_request'
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      with:
+        ref: ${{ github.event.pull_request.base.sha }}
+        path: old
+    # not a PR: use the previous commit as the old commit
+    - name: Checkout previous commit
+      if: github.event_name != 'pull_request'
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      with:
+        fetch-depth: 2
+        path: old
+    - name: Checkout previous commit
+      if: github.event_name != 'pull_request'
+      run: git -C old reset --hard HEAD^
+
+    - name: Checkout new commit
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      with:
+        path: new
+    - name: Install circular import checker
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      with:
+        repository: haampie/circular-import-fighter
+        ref: b5d6ce9be35f602cca7d5a6aa0259fca10639cca
+        path: circular-import-fighter
+    - name: Install dependencies
+      working-directory: circular-import-fighter
+      run: make -j dependencies
+    - name: Problematic imports before
+      working-directory: circular-import-fighter
+      run: make SPACK_ROOT=../old SUFFIX=.old
+    - name: Problematic imports after
+      working-directory: circular-import-fighter
+      run: make SPACK_ROOT=../new SUFFIX=.new
+    - name: Compare import cycles
+      working-directory: circular-import-fighter
+      run: |
+        edges_before="$(head -n1 solution.old)"
+        edges_after="$(head -n1 solution.new)"
+        if [ "$edges_after" -gt "$edges_before" ]; then
+          printf '\033[1;31mImport check failed: %s imports need to be deleted, ' "$edges_after"
+          printf 'previously this was %s\033[0m\n'  "$edges_before"
+          printf 'Compare \033[1;97m"Problematic imports before"\033[0m and '
+          printf '\033[1;97m"Problematic imports after"\033[0m.\n'
+          exit 1
+        else
+          printf '\033[1;32mImport check passed: %s <= %s\033[0m\n' "$edges_after" "$edges_before"
+        fi
 
   # Further style checks from pylint
   pylint:

etc/spack/defaults/concretizer.yaml

@@ -63,7 +63,3 @@ concretizer:
   # Setting this to false yields unreproducible results, so we advise to use that value only
   # for debugging purposes (e.g. check which constraints can help Spack concretize faster).
   error_on_timeout: true
-
-  # Static analysis may reduce the concretization time by generating smaller ASP problems, in
-  # cases where there are requirements that prevent part of the search space to be explored.
-  static_analysis: false

etc/spack/defaults/windows/config.yaml

@@ -1,5 +1,5 @@
 config:
   locks: false
   build_stage::
-    - '$user_cache_path/stage'
+    - '$spack/.staging'
   stage_name: '{name}-{version}-{hash:7}'

lib/spack/docs/build_systems/autotoolspackage.rst

@@ -272,9 +272,9 @@ often lists dependencies and the flags needed to locate them. The
 "environment variables" section lists environment variables that the
 build system uses to pass flags to the compiler and linker.
 
-^^^^^^^^^^^^^^^^^^^^^^^^^
-Adding flags to configure
-^^^^^^^^^^^^^^^^^^^^^^^^^
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+Addings flags to configure
+^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 For most of the flags you encounter, you will want a variant to
 optionally enable/disable them. You can then optionally pass these
@@ -285,7 +285,7 @@ function like so:
 
    def configure_args(self):
        args = []
-       ...
+
        if self.spec.satisfies("+mpi"):
            args.append("--enable-mpi")
        else:
@@ -299,10 +299,7 @@ Alternatively, you can use the :ref:`enable_or_disable  <autotools_enable_or_dis
 .. code-block:: python
 
    def configure_args(self):
-       args = []
-       ...
-       args.extend(self.enable_or_disable("mpi"))
-       return args
+       return [self.enable_or_disable("mpi")]
 
 
 Note that we are explicitly disabling MPI support if it is not
@@ -347,14 +344,7 @@ typically used to enable or disable some feature within the package.
        default=False,
        description="Memchecker support for debugging [degrades performance]"
    )
-   ...
-
-   def configure_args(self):
-       args = []
-       ...
-       args.extend(self.enable_or_disable("memchecker"))
-
-       return args
+   config_args.extend(self.enable_or_disable("memchecker"))
 
 In this example, specifying the variant ``+memchecker`` will generate
 the following configuration options:

lib/spack/docs/contribution_guide.rst

@@ -361,6 +361,7 @@ and the tags associated with the class of runners to build on.
     * ``.linux_neoverse_n1``
     * ``.linux_neoverse_v1``
     * ``.linux_neoverse_v2``
+    * ``.linux_power``
     * ``.linux_skylake``
     * ``.linux_x86_64``
     * ``.linux_x86_64_v4``

lib/spack/docs/environments.rst

@@ -112,19 +112,6 @@ the original but may concretize differently in the presence of different
 explicit or default configuration settings (e.g., a different version of
 Spack or for a different user account).
 
-Environments created from a manifest will copy any included configs
-from relative paths inside the environment. Relative paths from
-outside the environment will cause errors, and absolute paths will be
-kept absolute. For example, if ``spack.yaml`` includes:
-
-.. code-block:: yaml
-
-   spack:
-     include: [./config.yaml]
-
-then the created environment will have its own copy of the file
-``config.yaml`` copied from the location in the original environment.
-
 Create an environment from a ``spack.lock`` file using:
 
 .. code-block:: console
@@ -173,7 +160,7 @@ accepts.  If an environment already exists then spack will simply activate it
 and ignore the create-specific flags.
 
 .. code-block:: console
-
+   
    $ spack env activate --create -p myenv
    # ...
    # [creates if myenv does not exist yet]
@@ -437,8 +424,8 @@ Developing Packages in a Spack Environment
 
 The ``spack develop`` command allows one to develop Spack packages in
 an environment. It requires a spec containing a concrete version, and
-will configure Spack to install the package from local source.
-If a version is not provided from the command line interface then spack
+will configure Spack to install the package from local source. 
+If a version is not provided from the command line interface then spack 
 will automatically pick the highest version the package has defined.
 This means any infinity versions (``develop``, ``main``, ``stable``) will be
 preferred in this selection process.
@@ -448,9 +435,9 @@ set, and Spack will ensure the package and its dependents are rebuilt
 any time the environment is installed if the package's local source
 code has been modified. Spack's native implementation to check for modifications
 is to check if ``mtime`` is newer than the installation.
-A custom check can be created by overriding the ``detect_dev_src_change`` method
-in your package class. This is particularly useful for projects using custom spack repo's
-to drive development and want to optimize performance.
+A custom check can be created by overriding the ``detect_dev_src_change`` method 
+in your package class. This is particularly useful for projects using custom spack repo's 
+to drive development and want to optimize performance. 
 
 Spack ensures that all instances of a
 developed package in the environment are concretized to match the
@@ -466,7 +453,7 @@ Further development on ``foo`` can be tested by re-installing the environment,
 and eventually committed and pushed to the upstream git repo.
 
 If the package being developed supports out-of-source builds then users can use the
-``--build_directory`` flag to control the location and name of the build directory.
+``--build_directory`` flag to control the location and name of the build directory. 
 This is a shortcut to set the ``package_attributes:build_directory`` in the
 ``packages`` configuration (see :ref:`assigning-package-attributes`).
 The supplied location will become the build-directory for that package in all future builds.

lib/spack/llnl/util/filesystem.py

@@ -668,7 +668,7 @@ def copy(src, dest, _permissions=False):
         _permissions (bool): for internal use only
 
     Raises:
-        OSError: if *src* does not match any files or directories
+        IOError: if *src* does not match any files or directories
         ValueError: if *src* matches multiple files but *dest* is
             not a directory
     """
@@ -679,7 +679,7 @@ def copy(src, dest, _permissions=False):
 
     files = glob.glob(src)
     if not files:
-        raise OSError("No such file or directory: '{0}'".format(src))
+        raise IOError("No such file or directory: '{0}'".format(src))
     if len(files) > 1 and not os.path.isdir(dest):
         raise ValueError(
             "'{0}' matches multiple files but '{1}' is not a directory".format(src, dest)
@@ -710,7 +710,7 @@ def install(src, dest):
         dest (str): the destination file or directory
 
     Raises:
-        OSError: if *src* does not match any files or directories
+        IOError: if *src* does not match any files or directories
         ValueError: if *src* matches multiple files but *dest* is
             not a directory
     """
@@ -748,7 +748,7 @@ def copy_tree(
         _permissions (bool): for internal use only
 
     Raises:
-        OSError: if *src* does not match any files or directories
+        IOError: if *src* does not match any files or directories
         ValueError: if *src* is a parent directory of *dest*
     """
     if _permissions:
@@ -762,7 +762,7 @@ def copy_tree(
 
     files = glob.glob(src)
     if not files:
-        raise OSError("No such file or directory: '{0}'".format(src))
+        raise IOError("No such file or directory: '{0}'".format(src))
 
     # For Windows hard-links and junctions, the source path must exist to make a symlink. Add
     # all symlinks to this list while traversing the tree, then when finished, make all
@@ -843,7 +843,7 @@ def install_tree(src, dest, symlinks=True, ignore=None):
         ignore (typing.Callable): function indicating which files to ignore
 
     Raises:
-        OSError: if *src* does not match any files or directories
+        IOError: if *src* does not match any files or directories
         ValueError: if *src* is a parent directory of *dest*
     """
     copy_tree(src, dest, symlinks=symlinks, ignore=ignore, _permissions=True)

lib/spack/llnl/util/link_tree.py

@@ -308,7 +308,7 @@ class LinkTree:
 
     def __init__(self, source_root):
         if not os.path.exists(source_root):
-            raise OSError("No such file or directory: '%s'", source_root)
+            raise IOError("No such file or directory: '%s'", source_root)
 
         self._root = source_root
 

lib/spack/llnl/util/lock.py

@@ -391,7 +391,7 @@ def _poll_lock(self, op: int) -> bool:
 
             return True
 
-        except OSError as e:
+        except IOError as e:
             # EAGAIN and EACCES == locked by another process (so try again)
             if e.errno not in (errno.EAGAIN, errno.EACCES):
                 raise

lib/spack/llnl/util/tty/log.py

@@ -344,6 +344,26 @@ def close(self):
             self.file.close()
 
 
+@contextmanager
+def replace_environment(env):
+    """Replace the current environment (`os.environ`) with `env`.
+
+    If `env` is empty (or None), this unsets all current environment
+    variables.
+    """
+    env = env or {}
+    old_env = os.environ.copy()
+    try:
+        os.environ.clear()
+        for name, val in env.items():
+            os.environ[name] = val
+        yield
+    finally:
+        os.environ.clear()
+        for name, val in old_env.items():
+            os.environ[name] = val
+
+
 def log_output(*args, **kwargs):
     """Context manager that logs its output to a file.
 
@@ -427,6 +447,7 @@ def __init__(
         self.echo = echo
         self.debug = debug
         self.buffer = buffer
+        self.env = env  # the environment to use for _writer_daemon
         self.filter_fn = filter_fn
 
         self._active = False  # used to prevent re-entry
@@ -498,20 +519,21 @@ def __enter__(self):
                 # just don't forward input if this fails
                 pass
 
-            self.process = multiprocessing.Process(
-                target=_writer_daemon,
-                args=(
-                    input_fd,
-                    read_fd,
-                    self.write_fd,
-                    self.echo,
-                    self.log_file,
-                    child_pipe,
-                    self.filter_fn,
-                ),
-            )
-            self.process.daemon = True  # must set before start()
-            self.process.start()
+            with replace_environment(self.env):
+                self.process = multiprocessing.Process(
+                    target=_writer_daemon,
+                    args=(
+                        input_fd,
+                        read_fd,
+                        self.write_fd,
+                        self.echo,
+                        self.log_file,
+                        child_pipe,
+                        self.filter_fn,
+                    ),
+                )
+                self.process.daemon = True  # must set before start()
+                self.process.start()
 
         finally:
             if input_fd:
@@ -707,7 +729,10 @@ class winlog:
     Does not support the use of 'v' toggling as nixlog does.
     """
 
-    def __init__(self, file_like=None, echo=False, debug=0, buffer=False, filter_fn=None):
+    def __init__(
+        self, file_like=None, echo=False, debug=0, buffer=False, env=None, filter_fn=None
+    ):
+        self.env = env
         self.debug = debug
         self.echo = echo
         self.logfile = file_like
@@ -764,10 +789,11 @@ def background_reader(reader, echo_writer, _kill):
                     reader.close()
 
             self._active = True
-            self._thread = Thread(
-                target=background_reader, args=(self.reader, self.echo_writer, self._kill)
-            )
-            self._thread.start()
+            with replace_environment(self.env):
+                self._thread = Thread(
+                    target=background_reader, args=(self.reader, self.echo_writer, self._kill)
+                )
+                self._thread.start()
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
@@ -892,7 +918,7 @@ def _writer_daemon(
                         try:
                             if stdin_file.read(1) == "v":
                                 echo = not echo
-                        except OSError as e:
+                        except IOError as e:
                             # If SIGTTIN is ignored, the system gives EIO
                             # to let the caller know the read failed b/c it
                             # was in the bg. Ignore that too.
@@ -987,7 +1013,7 @@ def wrapped(*args, **kwargs):
         while True:
             try:
                 return function(*args, **kwargs)
-            except OSError as e:
+            except IOError as e:
                 if e.errno == errno.EINTR:
                     continue
                 raise

lib/spack/spack/__init__.py

@@ -10,7 +10,7 @@
 import spack.util.git
 
 #: PEP440 canonical <major>.<minor>.<micro>.<devN> string
-__version__ = "1.0.0.dev0"
+__version__ = "0.24.0.dev0"
 spack_version = __version__
 
 

lib/spack/spack/audit.py

@@ -1010,7 +1010,7 @@ def _issues_in_depends_on_directive(pkgs, error_cls):
             for dep_name, dep in deps_by_name.items():
 
                 def check_virtual_with_variants(spec, msg):
-                    if not spack.repo.PATH.is_virtual(spec.name) or not spec.variants:
+                    if not spec.virtual or not spec.variants:
                         return
                     error = error_cls(
                         f"{pkg_name}: {msg}",

lib/spack/spack/binary_distribution.py

@@ -2529,10 +2529,10 @@ def install_root_node(
         allow_missing: when true, allows installing a node with missing dependencies
     """
     # Early termination
-    if spec.external or not spec.concrete:
-        warnings.warn("Skipping external or abstract spec {0}".format(spec.format()))
+    if spec.external or spec.virtual:
+        warnings.warn("Skipping external or virtual package {0}".format(spec.format()))
         return
-    elif spec.installed and not force:
+    elif spec.concrete and spec.installed and not force:
         warnings.warn("Package for spec {0} already installed.".format(spec.format()))
         return
 

lib/spack/spack/bootstrap/clingo.py

@@ -27,9 +27,9 @@
 class ClingoBootstrapConcretizer:
     def __init__(self, configuration):
         self.host_platform = spack.platforms.host()
-        self.host_os = self.host_platform.default_operating_system()
+        self.host_os = self.host_platform.operating_system("frontend")
         self.host_target = archspec.cpu.host().family
-        self.host_architecture = spack.spec.ArchSpec.default_arch()
+        self.host_architecture = spack.spec.ArchSpec.frontend_arch()
         self.host_architecture.target = str(self.host_target)
         self.host_compiler = self._valid_compiler_or_raise()
         self.host_python = self.python_external_spec()

lib/spack/spack/bootstrap/config.py

@@ -141,7 +141,7 @@ def _bootstrap_config_scopes() -> Sequence["spack.config.ConfigScope"]:
 
 
 def _add_compilers_if_missing() -> None:
-    arch = spack.spec.ArchSpec.default_arch()
+    arch = spack.spec.ArchSpec.frontend_arch()
     if not spack.compilers.compilers_for_arch(arch):
         spack.compilers.find_compilers()
 

lib/spack/spack/build_systems/cmake.py

@@ -11,7 +11,6 @@
 from typing import Any, List, Optional, Tuple
 
 import llnl.util.filesystem as fs
-from llnl.util import tty
 from llnl.util.lang import stable_partition
 
 import spack.builder
@@ -459,23 +458,11 @@ def cmake(
     ) -> None:
         """Runs ``cmake`` in the build directory"""
 
-        if spec.is_develop:
-            # skip cmake phase if it is an incremental develop build
-
-            # Determine the files that will re-run CMake that are generated from a successful
-            # configure step based on state
-            primary_generator = _extract_primary_generator(self.generator)
-            configure_artifact = "Makefile"
-            if primary_generator == "Ninja":
-                configure_artifact = "ninja.build"
-
-            if os.path.isfile(os.path.join(self.build_directory, configure_artifact)):
-                tty.msg(
-                    "Incremental build criteria satisfied."
-                    "Skipping CMake configure step. To force configuration run"
-                    f" `spack clean {pkg.name}`"
-                )
-                return
+        # skip cmake phase if it is an incremental develop build
+        if spec.is_develop and os.path.isfile(
+            os.path.join(self.build_directory, "CMakeCache.txt")
+        ):
+            return
 
         options = self.std_cmake_args
         options += self.cmake_args()

lib/spack/spack/build_systems/cuda.py

@@ -15,7 +15,7 @@ class CudaPackage(PackageBase):
     """Auxiliary class which contains CUDA variant, dependencies and conflicts
     and is meant to unify and facilitate its usage.
 
-    Maintainers: ax3l, Rombur, davidbeckingsale, pauleonix
+    Maintainers: ax3l, Rombur, davidbeckingsale
     """
 
     # https://docs.nvidia.com/cuda/cuda-compiler-driver-nvcc/index.html#gpu-feature-list
@@ -47,12 +47,6 @@ class CudaPackage(PackageBase):
         "89",
         "90",
         "90a",
-        "100",
-        "100a",
-        "101",
-        "101a",
-        "120",
-        "120a",
     )
 
     # FIXME: keep cuda and cuda_arch separate to make usage easier until
@@ -105,56 +99,39 @@ def compute_capabilities(arch_list: Iterable[str]) -> List[str]:
     # CUDA version vs Architecture
     # https://en.wikipedia.org/wiki/CUDA#GPUs_supported
     # https://docs.nvidia.com/cuda/cuda-toolkit-release-notes/index.html#deprecated-features
-    # Tesla support:
     depends_on("cuda@:6.0", when="cuda_arch=10")
     depends_on("cuda@:6.5", when="cuda_arch=11")
     depends_on("cuda@2.1:6.5", when="cuda_arch=12")
     depends_on("cuda@2.1:6.5", when="cuda_arch=13")
 
-    # Fermi support:
     depends_on("cuda@3.0:8.0", when="cuda_arch=20")
     depends_on("cuda@3.2:8.0", when="cuda_arch=21")
 
-    # Kepler support:
     depends_on("cuda@5.0:10.2", when="cuda_arch=30")
     depends_on("cuda@5.0:10.2", when="cuda_arch=32")
     depends_on("cuda@5.0:11.8", when="cuda_arch=35")
     depends_on("cuda@6.5:11.8", when="cuda_arch=37")
 
-    # Maxwell support:
     depends_on("cuda@6.0:", when="cuda_arch=50")
     depends_on("cuda@6.5:", when="cuda_arch=52")
     depends_on("cuda@6.5:", when="cuda_arch=53")
 
-    # Pascal support:
     depends_on("cuda@8.0:", when="cuda_arch=60")
     depends_on("cuda@8.0:", when="cuda_arch=61")
     depends_on("cuda@8.0:", when="cuda_arch=62")
 
-    # Volta support:
     depends_on("cuda@9.0:", when="cuda_arch=70")
-    # Turing support:
     depends_on("cuda@9.0:", when="cuda_arch=72")
     depends_on("cuda@10.0:", when="cuda_arch=75")
 
-    # Ampere support:
     depends_on("cuda@11.0:", when="cuda_arch=80")
     depends_on("cuda@11.1:", when="cuda_arch=86")
     depends_on("cuda@11.4:", when="cuda_arch=87")
-    # Ada support:
     depends_on("cuda@11.8:", when="cuda_arch=89")
 
-    # Hopper support:
     depends_on("cuda@12.0:", when="cuda_arch=90")
     depends_on("cuda@12.0:", when="cuda_arch=90a")
 
-    # Blackwell support:
-    depends_on("cuda@12.8:", when="cuda_arch=100")
-    depends_on("cuda@12.8:", when="cuda_arch=100a")
-    depends_on("cuda@12.8:", when="cuda_arch=101")
-    depends_on("cuda@12.8:", when="cuda_arch=101a")
-    depends_on("cuda@12.8:", when="cuda_arch=120")
-    depends_on("cuda@12.8:", when="cuda_arch=120a")
     # From the NVIDIA install guide we know of conflicts for particular
     # platforms (linux, darwin), architectures (x86, powerpc) and compilers
     # (gcc, clang). We don't restrict %gcc and %clang conflicts to
@@ -186,7 +163,6 @@ def compute_capabilities(arch_list: Iterable[str]) -> List[str]:
         conflicts("%gcc@12:", when="+cuda ^cuda@:11.8")
         conflicts("%gcc@13:", when="+cuda ^cuda@:12.3")
         conflicts("%gcc@14:", when="+cuda ^cuda@:12.6")
-        conflicts("%gcc@15:", when="+cuda ^cuda@:12.8")
         conflicts("%clang@12:", when="+cuda ^cuda@:11.4.0")
         conflicts("%clang@13:", when="+cuda ^cuda@:11.5")
         conflicts("%clang@14:", when="+cuda ^cuda@:11.7")
@@ -195,7 +171,6 @@ def compute_capabilities(arch_list: Iterable[str]) -> List[str]:
         conflicts("%clang@17:", when="+cuda ^cuda@:12.3")
         conflicts("%clang@18:", when="+cuda ^cuda@:12.5")
         conflicts("%clang@19:", when="+cuda ^cuda@:12.6")
-        conflicts("%clang@20:", when="+cuda ^cuda@:12.8")
 
         # https://gist.github.com/ax3l/9489132#gistcomment-3860114
         conflicts("%gcc@10", when="+cuda ^cuda@:11.4.0")

lib/spack/spack/build_systems/python.py

@@ -264,17 +264,16 @@ def update_external_dependencies(self, extendee_spec=None):
                     # Ensure architecture information is present
                     if not python.architecture:
                         host_platform = spack.platforms.host()
-                        host_os = host_platform.default_operating_system()
-                        host_target = host_platform.default_target()
+                        host_os = host_platform.operating_system("default_os")
+                        host_target = host_platform.target("default_target")
                         python.architecture = spack.spec.ArchSpec(
                             (str(host_platform), str(host_os), str(host_target))
                         )
                     else:
                         if not python.architecture.platform:
                             python.architecture.platform = spack.platforms.host()
-                        platform = spack.platforms.by_name(python.architecture.platform)
                         if not python.architecture.os:
-                            python.architecture.os = platform.default_operating_system()
+                            python.architecture.os = "default_os"
                         if not python.architecture.target:
                             python.architecture.target = archspec.cpu.host().family.name
 

lib/spack/spack/ci/__init__.py

@@ -14,9 +14,8 @@
 import zipfile
 from collections import namedtuple
 from typing import Callable, Dict, List, Set
-from urllib.request import Request
+from urllib.request import HTTPHandler, Request, build_opener
 
-import llnl.path
 import llnl.util.filesystem as fs
 import llnl.util.tty as tty
 from llnl.util.tty.color import cescape, colorize
@@ -63,8 +62,6 @@
 
 PushResult = namedtuple("PushResult", "success url")
 
-urlopen = web_util.urlopen  # alias for mocking in tests
-
 
 def get_change_revisions():
     """If this is a git repo get the revisions to use when checking
@@ -84,9 +81,6 @@ def get_stack_changed(env_path, rev1="HEAD^", rev2="HEAD"):
     whether or not the stack was changed.  Returns True if the environment
     manifest changed between the provided revisions (or additionally if the
     `.gitlab-ci.yml` file itself changed).  Returns False otherwise."""
-    # git returns posix paths always, normalize input to be comptaible
-    # with that
-    env_path = llnl.path.convert_to_posix_path(env_path)
     git = spack.util.git.git()
     if git:
         with fs.working_dir(spack.paths.prefix):
@@ -633,19 +627,29 @@ def download_and_extract_artifacts(url, work_dir):
     if token:
         headers["PRIVATE-TOKEN"] = token
 
-    request = Request(url, headers=headers, method="GET")
+    opener = build_opener(HTTPHandler)
+
+    request = Request(url, headers=headers)
+    request.get_method = lambda: "GET"
+
+    response = opener.open(request, timeout=SPACK_CDASH_TIMEOUT)
+    response_code = response.getcode()
+
+    if response_code != 200:
+        msg = f"Error response code ({response_code}) in reproduce_ci_job"
+        raise SpackError(msg)
+
     artifacts_zip_path = os.path.join(work_dir, "artifacts.zip")
-    os.makedirs(work_dir, exist_ok=True)
 
-    try:
-        response = urlopen(request, timeout=SPACK_CDASH_TIMEOUT)
-        with open(artifacts_zip_path, "wb") as out_file:
-            shutil.copyfileobj(response, out_file)
-    except OSError as e:
-        raise SpackError(f"Error fetching artifacts: {e}")
+    if not os.path.exists(work_dir):
+        os.makedirs(work_dir)
 
-    with zipfile.ZipFile(artifacts_zip_path) as zip_file:
-        zip_file.extractall(work_dir)
+    with open(artifacts_zip_path, "wb") as out_file:
+        shutil.copyfileobj(response, out_file)
+
+    zip_file = zipfile.ZipFile(artifacts_zip_path)
+    zip_file.extractall(work_dir)
+    zip_file.close()
 
     os.remove(artifacts_zip_path)
 

lib/spack/spack/cmd/arch.py

@@ -3,7 +3,6 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 import collections
-import warnings
 
 import archspec.cpu
 
@@ -52,10 +51,10 @@ def setup_parser(subparser):
         "-t", "--target", action="store_true", default=False, help="print only the target"
     )
     parts2.add_argument(
-        "-f", "--frontend", action="store_true", default=False, help="print frontend (DEPRECATED)"
+        "-f", "--frontend", action="store_true", default=False, help="print frontend"
     )
     parts2.add_argument(
-        "-b", "--backend", action="store_true", default=False, help="print backend (DEPRECATED)"
+        "-b", "--backend", action="store_true", default=False, help="print backend"
     )
 
 
@@ -99,14 +98,15 @@ def arch(parser, args):
         display_targets(archspec.cpu.TARGETS)
         return
 
+    os_args, target_args = "default_os", "default_target"
     if args.frontend:
-        warnings.warn("the argument --frontend is deprecated, and will be removed in Spack v1.0")
+        os_args, target_args = "frontend", "frontend"
     elif args.backend:
-        warnings.warn("the argument --backend is deprecated, and will be removed in Spack v1.0")
+        os_args, target_args = "backend", "backend"
 
     host_platform = spack.platforms.host()
-    host_os = host_platform.default_operating_system()
-    host_target = host_platform.default_target()
+    host_os = host_platform.operating_system(os_args)
+    host_target = host_platform.target(target_args)
     if args.family:
         host_target = host_target.family
     elif args.generic:

lib/spack/spack/cmd/debug.py

@@ -86,8 +86,8 @@ def create_db_tarball(args):
 
 def report(args):
     host_platform = spack.platforms.host()
-    host_os = host_platform.default_operating_system()
-    host_target = host_platform.default_target()
+    host_os = host_platform.operating_system("frontend")
+    host_target = host_platform.target("frontend")
     architecture = spack.spec.ArchSpec((str(host_platform), str(host_os), str(host_target)))
     print("* **Spack:**", spack.get_version())
     print("* **Python:**", platform.python_version())

lib/spack/spack/cmd/dependencies.py

@@ -9,9 +9,9 @@
 
 import spack.cmd
 import spack.environment as ev
+import spack.package_base
 import spack.store
 from spack.cmd.common import arguments
-from spack.solver.input_analysis import create_graph_analyzer
 
 description = "show dependencies of a package"
 section = "basic"
@@ -68,17 +68,15 @@ def dependencies(parser, args):
 
     else:
         spec = specs[0]
-        dependencies, virtuals, _ = create_graph_analyzer().possible_dependencies(
+        dependencies = spack.package_base.possible_dependencies(
             spec,
             transitive=args.transitive,
             expand_virtuals=args.expand_virtuals,
-            allowed_deps=args.deptype,
+            depflag=args.deptype,
         )
-        if not args.expand_virtuals:
-            dependencies.update(virtuals)
 
         if spec.name in dependencies:
-            dependencies.remove(spec.name)
+            del dependencies[spec.name]
 
         if dependencies:
             colify(sorted(dependencies))

lib/spack/spack/cmd/develop.py

@@ -125,7 +125,7 @@ def develop(parser, args):
     version = spec.versions.concrete_range_as_version
     if not version:
         # look up the maximum version so infintiy versions are preferred for develop
-        version = max(spack.repo.PATH.get_pkg_class(spec.fullname).versions.keys())
+        version = max(spec.package_class.versions.keys())
         tty.msg(f"Defaulting to highest version: {spec.name}@{version}")
     spec.versions = spack.version.VersionList([version])
 

lib/spack/spack/cmd/external.py

@@ -110,7 +110,10 @@ def external_find(args):
             # Note that KeyboardInterrupt does not subclass Exception
             # (so CTRL-C will terminate the program as expected).
             skip_msg = "Skipping manifest and continuing with other external checks"
-            if isinstance(e, OSError) and e.errno in (errno.EPERM, errno.EACCES):
+            if (isinstance(e, IOError) or isinstance(e, OSError)) and e.errno in [
+                errno.EPERM,
+                errno.EACCES,
+            ]:
                 # The manifest file does not have sufficient permissions enabled:
                 # print a warning and keep going
                 tty.warn("Unable to read manifest due to insufficient permissions.", skip_msg)

lib/spack/spack/cmd/help.py

@@ -54,6 +54,10 @@
       @m{target=target}                 specific <target> processor
       @m{arch=platform-os-target}       shortcut for all three above
 
+    cross-compiling:
+      @m{os=backend} or @m{os=be}           build for compute node (backend)
+      @m{os=frontend} or @m{os=fe}          build for login node (frontend)
+
     dependencies:
       ^dependency [constraints]     specify constraints on dependencies
       ^@K{/hash}                        build with a specific installed

lib/spack/spack/cmd/mirror.py

@@ -545,7 +545,7 @@ def _not_license_excluded(self, x):
         package does not explicitly forbid redistributing source."""
         if self.private:
             return True
-        elif spack.repo.PATH.get_pkg_class(x.fullname).redistribute_source(x):
+        elif x.package_class.redistribute_source(x):
             return True
         else:
             tty.debug(

lib/spack/spack/cmd/providers.py

@@ -41,11 +41,7 @@ def providers(parser, args):
     specs = spack.cmd.parse_specs(args.virtual_package)
 
     # Check prerequisites
-    non_virtual = [
-        str(s)
-        for s in specs
-        if not spack.repo.PATH.is_virtual(s.name) or s.name not in valid_virtuals
-    ]
+    non_virtual = [str(s) for s in specs if not s.virtual or s.name not in valid_virtuals]
     if non_virtual:
         msg = "non-virtual specs cannot be part of the query "
         msg += "[{0}]\n".format(", ".join(non_virtual))

lib/spack/spack/cmd/style.py

@@ -6,7 +6,7 @@
 import os
 import re
 import sys
-from itertools import islice, zip_longest
+from itertools import zip_longest
 from typing import Dict, List, Optional
 
 import llnl.util.tty as tty
@@ -423,8 +423,7 @@ def _run_import_check(
             continue
 
         for m in is_abs_import.finditer(contents):
-            # Find at most two occurences: the first is the import itself, the second is its usage.
-            if len(list(islice(re.finditer(rf"{re.escape(m.group(1))}(?!\w)", contents), 2))) == 1:
+            if contents.count(m.group(1)) == 1:
                 to_remove.append(m.group(0))
                 exit_code = 1
                 print(f"{pretty_path}: redundant import: {m.group(1)}", file=out)
@@ -439,7 +438,7 @@ def _run_import_check(
             module = _module_part(root, m.group(0))
             if not module or module in to_add:
                 continue
-            if re.search(rf"import {re.escape(module)}(?!\w|\.)", contents):
+            if re.search(rf"import {re.escape(module)}\b(?!\.)", contents):
                 continue
             to_add.add(module)
             exit_code = 1

lib/spack/spack/cmd/test.py

@@ -177,15 +177,16 @@ def test_run(args):
         matching = spack.store.STORE.db.query_local(spec, hashes=hashes, explicit=explicit)
         if spec and not matching:
             tty.warn("No {0}installed packages match spec {1}".format(explicit_str, spec))
+            """
+            TODO: Need to write out a log message and/or CDASH Testing
+              output that package not installed IF continue to process
+              these issues here.
 
-            # TODO: Need to write out a log message and/or CDASH Testing
-            #   output that package not installed IF continue to process
-            #   these issues here.
-
-            # if args.log_format:
-            #     # Proceed with the spec assuming the test process
-            #     # to ensure report package as skipped (e.g., for CI)
-            #     specs_to_test.append(spec)
+            if args.log_format:
+                # Proceed with the spec assuming the test process
+                # to ensure report package as skipped (e.g., for CI)
+                specs_to_test.append(spec)
+            """
 
         specs_to_test.extend(matching)
 
@@ -252,9 +253,7 @@ def has_test_and_tags(pkg_class):
     hashes = env.all_hashes() if env else None
 
     specs = spack.store.STORE.db.query(hashes=hashes)
-    specs = list(
-        filter(lambda s: has_test_and_tags(spack.repo.PATH.get_pkg_class(s.fullname)), specs)
-    )
+    specs = list(filter(lambda s: has_test_and_tags(s.package_class), specs))
 
     spack.cmd.display_specs(specs, long=True)
 

lib/spack/spack/compilers/__init__.py

@@ -801,17 +801,17 @@ def _extract_compiler_paths(spec: "spack.spec.Spec") -> Optional[Dict[str, str]]
     def _extract_os_and_target(spec: "spack.spec.Spec"):
         if not spec.architecture:
             host_platform = spack.platforms.host()
-            operating_system = host_platform.default_operating_system()
-            target = host_platform.default_target()
+            operating_system = host_platform.operating_system("default_os")
+            target = host_platform.target("default_target")
         else:
             target = spec.architecture.target
             if not target:
-                target = spack.platforms.host().default_target()
+                target = spack.platforms.host().target("default_target")
 
             operating_system = spec.os
             if not operating_system:
                 host_platform = spack.platforms.host()
-                operating_system = host_platform.default_operating_system()
+                operating_system = host_platform.operating_system("default_os")
         return operating_system, target
 
 

lib/spack/spack/concretize.py

@@ -220,7 +220,7 @@ def concretize_one(spec: Union[str, Spec], tests: TestsType = False) -> Spec:
     opt, i, answer = min(result.answers)
     name = spec.name
     # TODO: Consolidate this code with similar code in solve.py
-    if spack.repo.PATH.is_virtual(spec.name):
+    if spec.virtual:
         providers = [s.name for s in answer.values() if s.package.provides(name)]
         name = providers[0]
 

lib/spack/spack/container/__init__.py

@@ -57,7 +57,7 @@ def validate(configuration_file):
     # Set the default value of the concretization strategy to unify and
     # warn if the user explicitly set another value
     env_dict.setdefault("concretizer", {"unify": True})
-    if env_dict["concretizer"]["unify"] is not True:
+    if not env_dict["concretizer"]["unify"] is True:
         warnings.warn(
             '"concretizer:unify" is not set to "true", which means the '
             "generated image may contain different variants of the same "

lib/spack/spack/database.py

@@ -41,8 +41,6 @@
     Union,
 )
 
-import spack.repo
-
 try:
     import uuid
 
@@ -1558,12 +1556,7 @@ def _query(
         # If we did fine something, the query spec can't be virtual b/c we matched an actual
         # package installation, so skip the virtual check entirely. If we *didn't* find anything,
         # check all the deferred specs *if* the query is virtual.
-        if (
-            not results
-            and query_spec is not None
-            and deferred
-            and spack.repo.PATH.is_virtual(query_spec.name)
-        ):
+        if not results and query_spec is not None and deferred and query_spec.virtual:
             results = [spec for spec in deferred if spec.satisfies(query_spec)]
 
         return results

lib/spack/spack/detection/path.py

@@ -259,8 +259,6 @@ def detect_specs(
             )
             return []
 
-        from spack.repo import PATH as repo_path
-
         result = []
         for candidate_path, items_in_prefix in _group_by_prefix(
             llnl.util.lang.dedupe(paths)
@@ -307,10 +305,7 @@ def detect_specs(
 
                 resolved_specs[spec] = candidate_path
                 try:
-                    # Validate the spec calling a package specific method
-                    pkg_cls = repo_path.get_pkg_class(spec.name)
-                    validate_fn = getattr(pkg_cls, "validate_detected_spec", lambda x, y: None)
-                    validate_fn(spec, spec.extra_attributes)
+                    spec.validate_detection()
                 except Exception as e:
                     msg = (
                         f'"{spec}" has been detected on the system but will '

lib/spack/spack/environment/environment.py

@@ -581,7 +581,7 @@ def _error_on_nonempty_view_dir(new_root):
     # Check if the target path lexists
     try:
         st = os.lstat(new_root)
-    except OSError:
+    except (IOError, OSError):
         return
 
     # Empty directories are fine
@@ -861,7 +861,7 @@ def regenerate(self, concrete_roots: List[Spec]) -> None:
         ):
             try:
                 shutil.rmtree(old_root)
-            except OSError as e:
+            except (IOError, OSError) as e:
                 msg = "Failed to remove old view at %s\n" % old_root
                 msg += str(e)
                 tty.warn(msg)
@@ -2554,7 +2554,7 @@ def is_latest_format(manifest):
     try:
         with open(manifest, encoding="utf-8") as f:
             data = syaml.load(f)
-    except OSError:
+    except (OSError, IOError):
         return True
     top_level_key = _top_level_key(data)
     changed = spack.schema.env.update(data[top_level_key])
@@ -2634,32 +2634,6 @@ def _ensure_env_dir():
 
     shutil.copy(envfile, target_manifest)
 
-    # Copy relative path includes that live inside the environment dir
-    try:
-        manifest = EnvironmentManifestFile(environment_dir)
-    except Exception:
-        # error handling for bad manifests is handled on other code paths
-        return
-
-    includes = manifest[TOP_LEVEL_KEY].get("include", [])
-    for include in includes:
-        if os.path.isabs(include):
-            continue
-
-        abspath = pathlib.Path(os.path.normpath(environment_dir / include))
-        common_path = pathlib.Path(os.path.commonpath([environment_dir, abspath]))
-        if common_path != environment_dir:
-            tty.debug(f"Will not copy relative include from outside environment: {include}")
-            continue
-
-        orig_abspath = os.path.normpath(envfile.parent / include)
-        if not os.path.exists(orig_abspath):
-            tty.warn(f"Included file does not exist; will not copy: '{include}'")
-            continue
-
-        fs.touchp(abspath)
-        shutil.copy(orig_abspath, abspath)
-
 
 class EnvironmentManifestFile(collections.abc.Mapping):
     """Manages the in-memory representation of a manifest file, and its synchronization

lib/spack/spack/extensions.py

@@ -187,7 +187,7 @@ def path_for_extension(target_name: str, *, paths: List[str]) -> str:
         if name == target_name:
             return path
     else:
-        raise OSError('extension "{0}" not found'.format(target_name))
+        raise IOError('extension "{0}" not found'.format(target_name))
 
 
 def get_module(cmd_name):

lib/spack/spack/filesystem_view.py

@@ -427,7 +427,7 @@ def needs_file(spec, file):
             try:
                 with open(manifest_file, "r", encoding="utf-8") as f:
                     manifest = s_json.load(f)
-            except OSError:
+            except (OSError, IOError):
                 # if we can't load it, assume it doesn't know about the file.
                 manifest = {}
             return test_path in manifest
@@ -831,7 +831,7 @@ def get_spec_from_file(filename):
     try:
         with open(filename, "r", encoding="utf-8") as f:
             return spack.spec.Spec.from_yaml(f)
-    except OSError:
+    except IOError:
         return None
 
 

lib/spack/spack/graph.py

@@ -42,10 +42,10 @@
 import llnl.util.tty.color
 
 import spack.deptypes as dt
+import spack.repo
 import spack.spec
 import spack.tengine
 import spack.traverse
-from spack.solver.input_analysis import create_graph_analyzer
 
 
 def find(seq, predicate):
@@ -537,11 +537,10 @@ def edge_entry(self, edge):
 
 def _static_edges(specs, depflag):
     for spec in specs:
-        *_, edges = create_graph_analyzer().possible_dependencies(
-            spec.name, expand_virtuals=True, allowed_deps=depflag
-        )
+        pkg_cls = spack.repo.PATH.get_pkg_class(spec.name)
+        possible = pkg_cls.possible_dependencies(expand_virtuals=True, depflag=depflag)
 
-        for parent_name, dependencies in edges.items():
+        for parent_name, dependencies in possible.items():
             for dependency_name in dependencies:
                 yield spack.spec.DependencySpec(
                     spack.spec.Spec(parent_name),

lib/spack/spack/hooks/absolutify_elf_sonames.py

@@ -26,7 +26,7 @@ def is_shared_library_elf(filepath):
         with open(filepath, "rb") as f:
             elf = parse_elf(f, interpreter=True, dynamic_section=True)
             return elf.has_pt_dynamic and (elf.has_soname or not elf.has_pt_interp)
-    except (OSError, ElfParsingError):
+    except (IOError, OSError, ElfParsingError):
         return False
 
 

lib/spack/spack/hooks/sbang.py

@@ -166,7 +166,7 @@ def filter_shebangs_in_directory(directory, filenames=None):
         # Only look at executable, non-symlink files.
         try:
             st = os.lstat(path)
-        except OSError:
+        except (IOError, OSError):
             continue
 
         if stat.S_ISLNK(st.st_mode) or stat.S_ISDIR(st.st_mode) or not st.st_mode & is_exe:

lib/spack/spack/install_test.py

@@ -566,7 +566,7 @@ def copy_test_files(pkg: Pb, test_spec: spack.spec.Spec):
 
     # copy test data into test stage data dir
     try:
-        pkg_cls = spack.repo.PATH.get_pkg_class(test_spec.fullname)
+        pkg_cls = test_spec.package_class
     except spack.repo.UnknownPackageError:
         tty.debug(f"{test_spec.name}: skipping test data copy since no package class found")
         return
@@ -623,7 +623,7 @@ def test_functions(
         vpkgs = virtuals(pkg)
         for vname in vpkgs:
             try:
-                classes.append(spack.repo.PATH.get_pkg_class(vname))
+                classes.append((Spec(vname)).package_class)
             except spack.repo.UnknownPackageError:
                 tty.debug(f"{vname}: virtual does not appear to have a package file")
 
@@ -668,7 +668,7 @@ def process_test_parts(pkg: Pb, test_specs: List[spack.spec.Spec], verbose: bool
 
             # grab test functions associated with the spec, which may be virtual
             try:
-                tests = test_functions(spack.repo.PATH.get_pkg_class(spec.fullname))
+                tests = test_functions(spec.package_class)
             except spack.repo.UnknownPackageError:
                 # Some virtuals don't have a package so we don't want to report
                 # them as not having tests when that isn't appropriate.

lib/spack/spack/installer.py

@@ -814,7 +814,7 @@ def get_depflags(self, pkg: "spack.package_base.PackageBase") -> int:
         # Include build dependencies if pkg is going to be built from sources, or
         # if build deps are explicitly requested.
         if include_build_deps or not (
-            cache_only or pkg.spec.installed and pkg.spec.dag_hash() not in self.overwrite
+            cache_only or pkg.spec.installed and not pkg.spec.dag_hash() in self.overwrite
         ):
             depflag |= dt.BUILD
         if self.run_tests(pkg):
@@ -2436,7 +2436,11 @@ def _real_install(self) -> None:
                     # DEBUGGING TIP - to debug this section, insert an IPython
                     # embed here, and run the sections below without log capture
                     log_contextmanager = log_output(
-                        log_file, self.echo, True, filter_fn=self.filter_fn
+                        log_file,
+                        self.echo,
+                        True,
+                        env=self.unmodified_env,
+                        filter_fn=self.filter_fn,
                     )
 
                     with log_contextmanager as logger:

lib/spack/spack/main.py

@@ -163,7 +163,7 @@ def format_help_sections(self, level):
         # lazily add all commands to the parser when needed.
         add_all_commands(self)
 
-        # Print help on subcommands in neatly formatted sections.
+        """Print help on subcommands in neatly formatted sections."""
         formatter = self._get_formatter()
 
         # Create a list of subcommand actions. Argparse internals are nasty!
@@ -728,7 +728,7 @@ def _compatible_sys_types():
     with the current host.
     """
     host_platform = spack.platforms.host()
-    host_os = str(host_platform.default_operating_system())
+    host_os = str(host_platform.operating_system("default_os"))
     host_target = archspec.cpu.host()
     compatible_targets = [host_target] + host_target.ancestors
 

lib/spack/spack/mirrors/mirror.py

@@ -64,7 +64,7 @@ def from_local_path(path: str):
     @staticmethod
     def from_url(url: str):
         """Create an anonymous mirror by URL. This method validates the URL."""
-        if urllib.parse.urlparse(url).scheme not in supported_url_schemes:
+        if not urllib.parse.urlparse(url).scheme in supported_url_schemes:
             raise ValueError(
                 f'"{url}" is not a valid mirror URL. '
                 f"Scheme must be one of {supported_url_schemes}."

lib/spack/spack/modules/lmod.py

@@ -209,7 +209,7 @@ def provides(self):
         # All the other tokens in the hierarchy must be virtual dependencies
         for x in self.hierarchy_tokens:
             if self.spec.package.provides(x):
-                provides[x] = self.spec
+                provides[x] = self.spec[x]
         return provides
 
     @property

lib/spack/spack/oci/opener.py

@@ -383,7 +383,6 @@ def create_opener():
     """Create an opener that can handle OCI authentication."""
     opener = urllib.request.OpenerDirector()
     for handler in [
-        urllib.request.ProxyHandler(),
         urllib.request.UnknownHandler(),
         urllib.request.HTTPSHandler(context=spack.util.web.ssl_create_default_context()),
         spack.util.web.SpackHTTPDefaultErrorHandler(),

lib/spack/spack/package.py

@@ -2,64 +2,31 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
-# flake8: noqa: F401, E402
-"""spack.package defines the public API for Spack packages, by re-exporting useful symbols from
-other modules. Packages should import this module, instead of importing from spack.* directly
-to ensure forward compatibility with future versions of Spack."""
+# flake8: noqa: F401
+"""spack.util.package is a set of useful build tools and directives for packages.
 
+Everything in this module is automatically imported into Spack package files.
+"""
 from os import chdir, environ, getcwd, makedirs, mkdir, remove, removedirs
 from shutil import move, rmtree
 
+from spack.error import InstallError, NoHeadersError, NoLibrariesError
+
+# Emulate some shell commands for convenience
+env = environ
+cd = chdir
+pwd = getcwd
+
 # import most common types used in packages
 from typing import Dict, List, Optional
 
-
-class tty:
-    import llnl.util.tty as _tty
-
-    debug = _tty.debug
-    error = _tty.error
-    info = _tty.info
-    msg = _tty.msg
-    warn = _tty.warn
-
-
-from llnl.util.filesystem import (
-    FileFilter,
-    FileList,
-    HeaderList,
-    LibraryList,
-    ancestor,
-    can_access,
-    change_sed_delimiter,
-    copy,
-    copy_tree,
-    filter_file,
-    find,
-    find_all_headers,
-    find_first,
-    find_headers,
-    find_libraries,
-    find_system_libraries,
-    force_remove,
-    force_symlink,
-    install,
-    install_tree,
-    is_exe,
-    join_path,
-    keep_modification_time,
-    library_extensions,
-    mkdirp,
-    remove_directory_contents,
-    remove_linked_tree,
-    rename,
-    set_executable,
-    set_install_permissions,
-    touch,
-    working_dir,
-)
+import llnl.util.filesystem
+from llnl.util.filesystem import *
 from llnl.util.symlink import symlink
 
+import spack.util.executable
+
+# These props will be overridden when the build env is set up.
 from spack.build_environment import MakeExecutable
 from spack.build_systems.aspell_dict import AspellDictPackage
 from spack.build_systems.autotools import AutotoolsPackage
@@ -109,24 +76,7 @@ class tty:
 from spack.builder import BaseBuilder
 from spack.config import determine_number_of_jobs
 from spack.deptypes import ALL_TYPES as all_deptypes
-from spack.directives import (
-    build_system,
-    can_splice,
-    conditional,
-    conflicts,
-    depends_on,
-    extends,
-    license,
-    maintainers,
-    patch,
-    provides,
-    redistribute,
-    requires,
-    resource,
-    variant,
-    version,
-)
-from spack.error import InstallError, NoHeadersError, NoLibrariesError
+from spack.directives import *
 from spack.install_test import (
     SkipTest,
     cache_extra_test_sources,
@@ -136,28 +86,26 @@ class tty:
     install_test_root,
     test_part,
 )
+from spack.installer import ExternalPackageError, InstallLockError, UpstreamPackageError
 from spack.mixins import filter_compiler_wrappers
 from spack.multimethod import default_args, when
-from spack.package_base import build_system_flags, env_flags, inject_flags, on_package_attributes
-from spack.package_completions import (
-    bash_completion_path,
-    fish_completion_path,
-    zsh_completion_path,
+from spack.package_base import (
+    DependencyConflictError,
+    build_system_flags,
+    env_flags,
+    flatten_dependencies,
+    inject_flags,
+    install_dependency_symlinks,
+    on_package_attributes,
 )
+from spack.package_completions import *
 from spack.phase_callbacks import run_after, run_before
-from spack.spec import Spec
-from spack.util.environment import EnvironmentModifications
-from spack.util.executable import Executable, ProcessError, which, which_string
+from spack.spec import InvalidSpecDetected, Spec
+from spack.util.executable import *
 from spack.util.filesystem import fix_darwin_install_name
-from spack.util.prefix import Prefix
 from spack.variant import any_combination_of, auto_or_any_combination_of, disjoint_sets
 from spack.version import Version, ver
 
-# Emulate some shell commands for convenience
-env = environ
-cd = chdir
-pwd = getcwd
-
 # These are just here for editor support; they may be set when the build env is set up.
 configure: Executable
 make_jobs: int

lib/spack/spack/package_base.py

@@ -22,6 +22,7 @@
 import textwrap
 import time
 import traceback
+import typing
 from typing import Any, Callable, Dict, Iterable, List, Optional, Set, Tuple, Type, TypeVar, Union
 
 from typing_extensions import Literal
@@ -29,6 +30,7 @@
 import llnl.util.filesystem as fsys
 import llnl.util.tty as tty
 from llnl.util.lang import classproperty, memoized
+from llnl.util.link_tree import LinkTree
 
 import spack.compilers
 import spack.config
@@ -65,6 +67,10 @@
 ]
 FLAG_HANDLER_TYPE = Callable[[str, Iterable[str]], FLAG_HANDLER_RETURN_TYPE]
 
+"""Allowed URL schemes for spack packages."""
+_ALLOWED_URL_SCHEMES = ["http", "https", "ftp", "file", "git"]
+
+
 #: Filename for the Spack build/install log.
 _spack_build_logfile = "spack-build-out.txt"
 
@@ -696,6 +702,9 @@ class PackageBase(WindowsRPath, PackageViewMixin, metaclass=PackageMeta):
     #: Verbosity level, preserved across installs.
     _verbose = None
 
+    #: index of patches by sha256 sum, built lazily
+    _patches_by_hash = None
+
     #: Package homepage where users can find more information about the package
     homepage: Optional[str] = None
 
@@ -709,6 +718,19 @@ class PackageBase(WindowsRPath, PackageViewMixin, metaclass=PackageMeta):
     #: Do not include @ here in order not to unnecessarily ping the users.
     maintainers: List[str] = []
 
+    #: List of attributes to be excluded from a package's hash.
+    metadata_attrs = [
+        "homepage",
+        "url",
+        "urls",
+        "list_url",
+        "extendable",
+        "parallel",
+        "make_jobs",
+        "maintainers",
+        "tags",
+    ]
+
     #: Set to ``True`` to indicate the stand-alone test requires a compiler.
     #: It is used to ensure a compiler and build dependencies like 'cmake'
     #: are available to build a custom test code.
@@ -808,6 +830,104 @@ def get_variant(self, name: str) -> spack.variant.Variant:
         except StopIteration:
             raise ValueError(f"No variant '{name}' on spec: {self.spec}")
 
+    @classmethod
+    def possible_dependencies(
+        cls,
+        transitive: bool = True,
+        expand_virtuals: bool = True,
+        depflag: dt.DepFlag = dt.ALL,
+        visited: Optional[dict] = None,
+        missing: Optional[dict] = None,
+        virtuals: Optional[set] = None,
+    ) -> Dict[str, Set[str]]:
+        """Return dict of possible dependencies of this package.
+
+        Args:
+            transitive (bool or None): return all transitive dependencies if
+                True, only direct dependencies if False (default True)..
+            expand_virtuals (bool or None): expand virtual dependencies into
+                all possible implementations (default True)
+            depflag: dependency types to consider
+            visited (dict or None): dict of names of dependencies visited so
+                far, mapped to their immediate dependencies' names.
+            missing (dict or None): dict to populate with packages and their
+                *missing* dependencies.
+            virtuals (set): if provided, populate with virtuals seen so far.
+
+        Returns:
+            (dict): dictionary mapping dependency names to *their*
+                immediate dependencies
+
+        Each item in the returned dictionary maps a (potentially
+        transitive) dependency of this package to its possible
+        *immediate* dependencies. If ``expand_virtuals`` is ``False``,
+        virtual package names wil be inserted as keys mapped to empty
+        sets of dependencies.  Virtuals, if not expanded, are treated as
+        though they have no immediate dependencies.
+
+        Missing dependencies by default are ignored, but if a
+        missing dict is provided, it will be populated with package names
+        mapped to any dependencies they have that are in no
+        repositories. This is only populated if transitive is True.
+
+        Note: the returned dict *includes* the package itself.
+
+        """
+        visited = {} if visited is None else visited
+        missing = {} if missing is None else missing
+
+        visited.setdefault(cls.name, set())
+
+        for name, conditions in cls.dependencies_by_name(when=True).items():
+            # check whether this dependency could be of the type asked for
+            depflag_union = 0
+            for deplist in conditions.values():
+                for dep in deplist:
+                    depflag_union |= dep.depflag
+            if not (depflag & depflag_union):
+                continue
+
+            # expand virtuals if enabled, otherwise just stop at virtuals
+            if spack.repo.PATH.is_virtual(name):
+                if virtuals is not None:
+                    virtuals.add(name)
+                if expand_virtuals:
+                    providers = spack.repo.PATH.providers_for(name)
+                    dep_names = [spec.name for spec in providers]
+                else:
+                    visited.setdefault(cls.name, set()).add(name)
+                    visited.setdefault(name, set())
+                    continue
+            else:
+                dep_names = [name]
+
+            # add the dependency names to the visited dict
+            visited.setdefault(cls.name, set()).update(set(dep_names))
+
+            # recursively traverse dependencies
+            for dep_name in dep_names:
+                if dep_name in visited:
+                    continue
+
+                visited.setdefault(dep_name, set())
+
+                # skip the rest if not transitive
+                if not transitive:
+                    continue
+
+                try:
+                    dep_cls = spack.repo.PATH.get_pkg_class(dep_name)
+                except spack.repo.UnknownPackageError:
+                    # log unknown packages
+                    missing.setdefault(cls.name, set()).add(dep_name)
+                    continue
+
+                dep_cls.possible_dependencies(
+                    transitive, expand_virtuals, depflag, visited, missing, virtuals
+                )
+
+        return visited
+
     @classproperty
     def package_dir(cls):
         """Directory where the package.py file lives."""
@@ -2172,6 +2292,85 @@ def rpath_args(self):
 build_system_flags = PackageBase.build_system_flags
 
 
+def install_dependency_symlinks(pkg, spec, prefix):
+    """
+    Execute a dummy install and flatten dependencies.
+
+    This routine can be used in a ``package.py`` definition by setting
+    ``install = install_dependency_symlinks``.
+
+    This feature comes in handy for creating a common location for the
+    the installation of third-party libraries.
+    """
+    flatten_dependencies(spec, prefix)
+
+
+def use_cray_compiler_names():
+    """Compiler names for builds that rely on cray compiler names."""
+    os.environ["CC"] = "cc"
+    os.environ["CXX"] = "CC"
+    os.environ["FC"] = "ftn"
+    os.environ["F77"] = "ftn"
+
+
+def flatten_dependencies(spec, flat_dir):
+    """Make each dependency of spec present in dir via symlink."""
+    for dep in spec.traverse(root=False):
+        name = dep.name
+
+        dep_path = spack.store.STORE.layout.path_for_spec(dep)
+        dep_files = LinkTree(dep_path)
+
+        os.mkdir(flat_dir + "/" + name)
+
+        conflict = dep_files.find_conflict(flat_dir + "/" + name)
+        if conflict:
+            raise DependencyConflictError(conflict)
+
+        dep_files.merge(flat_dir + "/" + name)
+
+
+def possible_dependencies(
+    *pkg_or_spec: Union[str, spack.spec.Spec, typing.Type[PackageBase]],
+    transitive: bool = True,
+    expand_virtuals: bool = True,
+    depflag: dt.DepFlag = dt.ALL,
+    missing: Optional[dict] = None,
+    virtuals: Optional[set] = None,
+) -> Dict[str, Set[str]]:
+    """Get the possible dependencies of a number of packages.
+
+    See ``PackageBase.possible_dependencies`` for details.
+    """
+    packages = []
+    for pos in pkg_or_spec:
+        if isinstance(pos, PackageMeta) and issubclass(pos, PackageBase):
+            packages.append(pos)
+            continue
+
+        if not isinstance(pos, spack.spec.Spec):
+            pos = spack.spec.Spec(pos)
+
+        if spack.repo.PATH.is_virtual(pos.name):
+            packages.extend(p.package_class for p in spack.repo.PATH.providers_for(pos.name))
+            continue
+        else:
+            packages.append(pos.package_class)
+
+    visited: Dict[str, Set[str]] = {}
+    for pkg in packages:
+        pkg.possible_dependencies(
+            visited=visited,
+            transitive=transitive,
+            expand_virtuals=expand_virtuals,
+            depflag=depflag,
+            missing=missing,
+            virtuals=virtuals,
+        )
+
+    return visited
+
+
 def deprecated_version(pkg: PackageBase, version: Union[str, StandardVersion]) -> bool:
     """Return True iff the version is deprecated.
 

lib/spack/spack/platforms/__init__.py

@@ -52,7 +52,8 @@ def use_platform(new_platform):
 
     import spack.config
 
-    assert isinstance(new_platform, Platform), f'"{new_platform}" must be an instance of Platform'
+    msg = '"{0}" must be an instance of Platform'
+    assert isinstance(new_platform, Platform), msg.format(new_platform)
 
     original_host_fn = host
 

lib/spack/spack/platforms/_platform.py

@@ -1,22 +1,42 @@
 # Copyright Spack Project Developers. See COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-import warnings
 from typing import Optional
 
 import archspec.cpu
 
 import llnl.util.lang
 
+import spack.error
+
+
+class NoPlatformError(spack.error.SpackError):
+    def __init__(self):
+        msg = "Could not determine a platform for this machine"
+        super().__init__(msg)
+
 
 @llnl.util.lang.lazy_lexicographic_ordering
 class Platform:
     """Platform is an abstract class extended by subclasses.
 
+    To add a new type of platform (such as cray_xe), create a subclass and set all the
+    class attributes such as priority, front_target, back_target, front_os, back_os.
+
     Platform also contain a priority class attribute. A lower number signifies higher
     priority. These numbers are arbitrarily set and can be changed though often there
     isn't much need unless a new platform is added and the user wants that to be
     detected first.
+
+    Targets are created inside the platform subclasses. Most architecture (like linux,
+    and darwin) will have only one target family (x86_64) but in the case of Cray
+    machines, there is both a frontend and backend processor. The user can specify
+    which targets are present on front-end and back-end architecture.
+
+    Depending on the platform, operating systems are either autodetected or are
+    set. The user can set the frontend and backend operating setting by the class
+    attributes front_os and back_os. The operating system will be responsible for
+    compiler detection.
     """
 
     # Subclass sets number. Controls detection order
@@ -25,72 +45,82 @@ class Platform:
     #: binary formats used on this platform; used by relocation logic
     binary_formats = ["elf"]
 
-    default: str
-    default_os: str
+    front_end: Optional[str] = None
+    back_end: Optional[str] = None
+    default: Optional[str] = None  # The default back end target.
+
+    front_os: Optional[str] = None
+    back_os: Optional[str] = None
+    default_os: Optional[str] = None
 
     reserved_targets = ["default_target", "frontend", "fe", "backend", "be"]
     reserved_oss = ["default_os", "frontend", "fe", "backend", "be"]
-    deprecated_names = ["frontend", "fe", "backend", "be"]
 
     def __init__(self, name):
         self.targets = {}
         self.operating_sys = {}
         self.name = name
-        self._init_targets()
 
     def add_target(self, name: str, target: archspec.cpu.Microarchitecture) -> None:
+        """Used by the platform specific subclass to list available targets.
+        Raises an error if the platform specifies a name
+        that is reserved by spack as an alias.
+        """
         if name in Platform.reserved_targets:
-            msg = f"{name} is a spack reserved alias and cannot be the name of a target"
-            raise ValueError(msg)
+            msg = "{0} is a spack reserved alias and cannot be the name of a target"
+            raise ValueError(msg.format(name))
         self.targets[name] = target
 
-    def _init_targets(self):
-        self.default = archspec.cpu.host().name
+    def _add_archspec_targets(self):
         for name, microarchitecture in archspec.cpu.TARGETS.items():
             self.add_target(name, microarchitecture)
 
     def target(self, name):
+        """This is a getter method for the target dictionary
+        that handles defaulting based on the values provided by default,
+        front-end, and back-end. This can be overwritten
+        by a subclass for which we want to provide further aliasing options.
+        """
+        # TODO: Check if we can avoid using strings here
         name = str(name)
-        if name in Platform.deprecated_names:
-            warnings.warn(f"target={name} is deprecated, use target={self.default} instead")
-
-        if name in Platform.reserved_targets:
+        if name == "default_target":
             name = self.default
+        elif name == "frontend" or name == "fe":
+            name = self.front_end
+        elif name == "backend" or name == "be":
+            name = self.back_end
 
         return self.targets.get(name, None)
 
     def add_operating_system(self, name, os_class):
-        if name in Platform.reserved_oss + Platform.deprecated_names:
-            msg = f"{name} is a spack reserved alias and cannot be the name of an OS"
-            raise ValueError(msg)
+        """Add the operating_system class object into the
+        platform.operating_sys dictionary.
+        """
+        if name in Platform.reserved_oss:
+            msg = "{0} is a spack reserved alias and cannot be the name of an OS"
+            raise ValueError(msg.format(name))
         self.operating_sys[name] = os_class
 
-    def default_target(self):
-        return self.target(self.default)
-
-    def default_operating_system(self):
-        return self.operating_system(self.default_os)
-
     def operating_system(self, name):
-        if name in Platform.deprecated_names:
-            warnings.warn(f"os={name} is deprecated, use os={self.default_os} instead")
-
-        if name in Platform.reserved_oss:
+        if name == "default_os":
             name = self.default_os
+        if name == "frontend" or name == "fe":
+            name = self.front_os
+        if name == "backend" or name == "be":
+            name = self.back_os
 
         return self.operating_sys.get(name, None)
 
     def setup_platform_environment(self, pkg, env):
-        """Platform-specific build environment modifications.
-
-        This method is meant toi be overridden by subclasses, when needed.
+        """Subclass can override this method if it requires any
+        platform-specific build environment modifications.
         """
         pass
 
     @classmethod
     def detect(cls):
-        """Returns True if the host platform is detected to be the current Platform class,
-        False otherwise.
+        """Return True if the the host platform is detected to be the current
+        Platform class, False otherwise.
 
         Derived classes are responsible for implementing this method.
         """
@@ -105,7 +135,11 @@ def __str__(self):
     def _cmp_iter(self):
         yield self.name
         yield self.default
+        yield self.front_end
+        yield self.back_end
         yield self.default_os
+        yield self.front_os
+        yield self.back_os
 
         def targets():
             for t in sorted(self.targets.values()):

lib/spack/spack/platforms/darwin.py

@@ -4,6 +4,8 @@
 
 import platform as py_platform
 
+import archspec.cpu
+
 from spack.operating_systems.mac_os import MacOs
 from spack.version import Version
 
@@ -17,8 +19,18 @@ class Darwin(Platform):
 
     def __init__(self):
         super().__init__("darwin")
+        self._add_archspec_targets()
+
+        self.default = archspec.cpu.host().name
+        self.front_end = self.default
+        self.back_end = self.default
+
         mac_os = MacOs()
+
         self.default_os = str(mac_os)
+        self.front_os = str(mac_os)
+        self.back_os = str(mac_os)
+
         self.add_operating_system(str(mac_os), mac_os)
 
     @classmethod

lib/spack/spack/platforms/freebsd.py

@@ -3,6 +3,8 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 import platform
 
+import archspec.cpu
+
 from spack.operating_systems.freebsd import FreeBSDOs
 
 from ._platform import Platform
@@ -13,8 +15,18 @@ class FreeBSD(Platform):
 
     def __init__(self):
         super().__init__("freebsd")
+
+        self._add_archspec_targets()
+
+        # Get specific default
+        self.default = archspec.cpu.host().name
+        self.front_end = self.default
+        self.back_end = self.default
+
         os = FreeBSDOs()
         self.default_os = str(os)
+        self.front_os = self.default_os
+        self.back_os = self.default_os
         self.add_operating_system(str(os), os)
 
     @classmethod

lib/spack/spack/platforms/linux.py

@@ -3,6 +3,8 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 import platform
 
+import archspec.cpu
+
 from spack.operating_systems.linux_distro import LinuxDistro
 
 from ._platform import Platform
@@ -13,8 +15,18 @@ class Linux(Platform):
 
     def __init__(self):
         super().__init__("linux")
+
+        self._add_archspec_targets()
+
+        # Get specific default
+        self.default = archspec.cpu.host().name
+        self.front_end = self.default
+        self.back_end = self.default
+
         linux_dist = LinuxDistro()
         self.default_os = str(linux_dist)
+        self.front_os = self.default_os
+        self.back_os = self.default_os
         self.add_operating_system(str(linux_dist), linux_dist)
 
     @classmethod

lib/spack/spack/platforms/test.py

@@ -16,19 +16,31 @@ class Test(Platform):
     if platform.system().lower() == "darwin":
         binary_formats = ["macho"]
 
+    if platform.machine() == "arm64":
+        front_end = "aarch64"
+        back_end = "m1"
+        default = "m1"
+    else:
+        front_end = "x86_64"
+        back_end = "core2"
+        default = "core2"
+
+    front_os = "redhat6"
+    back_os = "debian6"
     default_os = "debian6"
-    default = "m1" if platform.machine() == "arm64" else "core2"
 
     def __init__(self, name=None):
         name = name or "test"
         super().__init__(name)
-        self.add_operating_system("debian6", spack.operating_systems.OperatingSystem("debian", 6))
-        self.add_operating_system("redhat6", spack.operating_systems.OperatingSystem("redhat", 6))
+        self.add_target(self.default, archspec.cpu.TARGETS[self.default])
+        self.add_target(self.front_end, archspec.cpu.TARGETS[self.front_end])
 
-    def _init_targets(self):
-        targets = ("aarch64", "m1") if platform.machine() == "arm64" else ("x86_64", "core2")
-        for t in targets:
-            self.add_target(t, archspec.cpu.TARGETS[t])
+        self.add_operating_system(
+            self.default_os, spack.operating_systems.OperatingSystem("debian", 6)
+        )
+        self.add_operating_system(
+            self.front_os, spack.operating_systems.OperatingSystem("redhat", 6)
+        )
 
     @classmethod
     def detect(cls):

lib/spack/spack/platforms/windows.py

@@ -4,6 +4,8 @@
 
 import platform
 
+import archspec.cpu
+
 from spack.operating_systems.windows_os import WindowsOs
 
 from ._platform import Platform
@@ -14,8 +16,18 @@ class Windows(Platform):
 
     def __init__(self):
         super().__init__("windows")
+        self._add_archspec_targets()
+
+        self.default = archspec.cpu.host().name
+        self.front_end = self.default
+        self.back_end = self.default
+
         windows_os = WindowsOs()
+
         self.default_os = str(windows_os)
+        self.front_os = str(windows_os)
+        self.back_os = str(windows_os)
+
         self.add_operating_system(str(windows_os), windows_os)
 
     @classmethod

lib/spack/spack/relocate.py

@@ -236,15 +236,22 @@ def relocate_elf_binaries(binaries: Iterable[str], prefix_to_prefix: Dict[str, s
             _set_elf_rpaths_and_interpreter(path, rpaths=rpaths, interpreter=interpreter)
 
 
+def _warn_if_link_cant_be_relocated(link: str, target: str):
+    if not os.path.isabs(target):
+        return
+    tty.warn(f'Symbolic link at "{link}" to "{target}" cannot be relocated')
+
+
 def relocate_links(links: Iterable[str], prefix_to_prefix: Dict[str, str]) -> None:
     """Relocate links to a new install prefix."""
     regex = re.compile("|".join(re.escape(p) for p in prefix_to_prefix.keys()))
     for link in links:
         old_target = readlink(link)
-        if not os.path.isabs(old_target):
-            continue
         match = regex.match(old_target)
+
+        # No match.
         if match is None:
+            _warn_if_link_cant_be_relocated(link, old_target)
             continue
 
         new_target = prefix_to_prefix[match.group()] + old_target[match.end() :]
@@ -406,8 +413,8 @@ def fixup_macos_rpaths(spec):
     entries which makes it harder to adjust with ``install_name_tool
     -delete_rpath``.
     """
-    if spec.external or not spec.concrete:
-        tty.warn("external/abstract spec cannot be fixed up: {0!s}".format(spec))
+    if spec.external or spec.virtual:
+        tty.warn("external or virtual package cannot be fixed up: {0!s}".format(spec))
         return False
 
     if "platform=darwin" not in spec:

lib/spack/spack/repo.py

@@ -1041,7 +1041,7 @@ def _read_config(self) -> Dict[str, str]:
 
                 return yaml_data["repo"]
 
-        except OSError:
+        except IOError:
             tty.die(f"Error reading {self.config_file} when opening {self.root}")
 
     def get(self, spec: "spack.spec.Spec") -> "spack.package_base.PackageBase":
@@ -1369,7 +1369,7 @@ def create_repo(root, namespace=None, subdir=packages_dir_name):
             if subdir != packages_dir_name:
                 config.write(f"  subdirectory: '{subdir}'\n")
 
-    except OSError as e:
+    except (IOError, OSError) as e:
         # try to clean up.
         if existed:
             shutil.rmtree(config_path, ignore_errors=True)

lib/spack/spack/reporters/cdash.py

@@ -1,7 +1,6 @@
 # Copyright Spack Project Developers. See COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-import codecs
 import collections
 import hashlib
 import os
@@ -14,7 +13,7 @@
 import xml.sax.saxutils
 from typing import Dict, Optional
 from urllib.parse import urlencode
-from urllib.request import Request
+from urllib.request import HTTPSHandler, Request, build_opener
 
 import llnl.util.tty as tty
 from llnl.util.filesystem import working_dir
@@ -25,10 +24,10 @@
 import spack.spec
 import spack.tengine
 import spack.util.git
-import spack.util.web as web_util
 from spack.error import SpackError
 from spack.util.crypto import checksum
 from spack.util.log_parse import parse_log_events
+from spack.util.web import ssl_create_default_context
 
 from .base import Reporter
 from .extract import extract_test_parts
@@ -107,7 +106,7 @@ def __init__(self, configuration: CDashConfiguration):
         self.site = configuration.site or socket.gethostname()
         self.osname = platform.system()
         self.osrelease = platform.release()
-        self.target = spack.platforms.host().default_target()
+        self.target = spack.platforms.host().target("default_target")
         self.starttime = int(time.time())
         self.endtime = self.starttime
         self.buildstamp = (
@@ -434,6 +433,7 @@ def upload(self, filename):
         # Compute md5 checksum for the contents of this file.
         md5sum = checksum(hashlib.md5, filename, block_size=8192)
 
+        opener = build_opener(HTTPSHandler(context=ssl_create_default_context()))
         with open(filename, "rb") as f:
             params_dict = {
                 "build": self.buildname,
@@ -443,21 +443,26 @@ def upload(self, filename):
             }
             encoded_params = urlencode(params_dict)
             url = "{0}&{1}".format(self.cdash_upload_url, encoded_params)
-            request = Request(url, data=f, method="PUT")
+            request = Request(url, data=f)
             request.add_header("Content-Type", "text/xml")
             request.add_header("Content-Length", os.path.getsize(filename))
             if self.authtoken:
                 request.add_header("Authorization", "Bearer {0}".format(self.authtoken))
             try:
-                response = web_util.urlopen(request, timeout=SPACK_CDASH_TIMEOUT)
+                # By default, urllib2 only support GET and POST.
+                # CDash expects this file to be uploaded via PUT.
+                request.get_method = lambda: "PUT"
+                response = opener.open(request, timeout=SPACK_CDASH_TIMEOUT)
                 if self.current_package_name not in self.buildIds:
-                    resp_value = codecs.getreader("utf-8")(response).read()
+                    resp_value = response.read()
+                    if isinstance(resp_value, bytes):
+                        resp_value = resp_value.decode("utf-8")
                     match = self.buildid_regexp.search(resp_value)
                     if match:
                         buildid = match.group(1)
                         self.buildIds[self.current_package_name] = buildid
             except Exception as e:
-                print(f"Upload to CDash failed: {e}")
+                print("Upload to CDash failed: {0}".format(e))
 
     def finalize_report(self):
         if self.buildIds:

lib/spack/spack/schema/concretizer.py

@@ -87,7 +87,6 @@
                     "strategy": {"type": "string", "enum": ["none", "minimal", "full"]}
                 },
             },
-            "static_analysis": {"type": "boolean"},
             "timeout": {"type": "integer", "minimum": 0},
             "error_on_timeout": {"type": "boolean"},
             "os_compatible": {"type": "object", "additionalProperties": {"type": "array"}},

lib/spack/spack/solver/asp.py

@@ -6,7 +6,6 @@
 import copy
 import enum
 import functools
-import io
 import itertools
 import os
 import pathlib
@@ -63,7 +62,7 @@
     parse_files,
     parse_term,
 )
-from .input_analysis import create_counter, create_graph_analyzer
+from .counter import FullDuplicatesCounter, MinimalDuplicatesCounter, NoDuplicatesCounter
 from .requirements import RequirementKind, RequirementParser, RequirementRule
 from .version_order import concretization_version_order
 
@@ -74,19 +73,17 @@
 #: Enable the addition of a runtime node
 WITH_RUNTIME = sys.platform != "win32"
 
-
-class OutputConfiguration(NamedTuple):
-    """Data class that contains configuration on what a clingo solve should output."""
-
-    #: Print out coarse timers for different solve phases
-    timers: bool
-    #: Whether to output Clingo's internal solver statistics
-    stats: bool
-    #: Optional output stream for the generated ASP program
-    out: Optional[io.IOBase]
-    #: If True, stop after setup and don't solve
-    setup_only: bool
-
+#: Data class that contain configuration on what a
+#: clingo solve should output.
+#:
+#: Args:
+#:     timers (bool):  Print out coarse timers for different solve phases.
+#:     stats (bool): Whether to output Clingo's internal solver statistics.
+#:     out: Optional output stream for the generated ASP program.
+#:     setup_only (bool): if True, stop after setup and don't solve (default False).
+OutputConfiguration = collections.namedtuple(
+    "OutputConfiguration", ["timers", "stats", "out", "setup_only"]
+)
 
 #: Default output configuration for a solve
 DEFAULT_OUTPUT_CONFIGURATION = OutputConfiguration(
@@ -274,6 +271,15 @@ def remove_node(spec: spack.spec.Spec, facts: List[AspFunction]) -> List[AspFunc
     return list(filter(lambda x: x.args[0] not in ("node", "virtual_node"), facts))
 
 
+def _create_counter(specs: List[spack.spec.Spec], tests: bool):
+    strategy = spack.config.CONFIG.get("concretizer:duplicates:strategy", "none")
+    if strategy == "full":
+        return FullDuplicatesCounter(specs, tests=tests)
+    if strategy == "minimal":
+        return MinimalDuplicatesCounter(specs, tests=tests)
+    return NoDuplicatesCounter(specs, tests=tests)
+
+
 def all_libcs() -> Set[spack.spec.Spec]:
     """Return a set of all libc specs targeted by any configured compiler. If none, fall back to
     libc determined from the current Python process if dynamically linked."""
@@ -501,7 +507,7 @@ def _compute_specs_from_answer_set(self):
             # The specs must be unified to get here, so it is safe to associate any satisfying spec
             # with the input. Multiple inputs may be matched to the same concrete spec
             node = SpecBuilder.make_node(pkg=input_spec.name)
-            if spack.repo.PATH.is_virtual(input_spec.name):
+            if input_spec.virtual:
                 providers = [
                     spec.name for spec in answer.values() if spec.package.provides(input_spec.name)
                 ]
@@ -1115,8 +1121,6 @@ class SpackSolverSetup:
     """Class to set up and run a Spack concretization solve."""
 
     def __init__(self, tests: bool = False):
-        self.possible_graph = create_graph_analyzer()
-
         # these are all initialized in setup()
         self.gen: "ProblemInstanceBuilder" = ProblemInstanceBuilder()
         self.requirement_parser = RequirementParser(spack.config.CONFIG)
@@ -2083,11 +2087,7 @@ def _spec_clauses(
         f: Union[Type[_Head], Type[_Body]] = _Body if body else _Head
 
         if spec.name:
-            clauses.append(
-                f.node(spec.name)
-                if not spack.repo.PATH.is_virtual(spec.name)
-                else f.virtual_node(spec.name)
-            )
+            clauses.append(f.node(spec.name) if not spec.virtual else f.virtual_node(spec.name))
         if spec.namespace:
             clauses.append(f.namespace(spec.name, spec.namespace))
 
@@ -2114,7 +2114,7 @@ def _spec_clauses(
 
             for value in variant.value_as_tuple:
                 # ensure that the value *can* be valid for the spec
-                if spec.name and not spec.concrete and not spack.repo.PATH.is_virtual(spec.name):
+                if spec.name and not spec.concrete and not spec.virtual:
                     variant_defs = vt.prevalidate_variant_value(
                         self.pkg_class(spec.name), variant, spec
                     )
@@ -2397,20 +2397,38 @@ def keyfun(os):
 
     def target_defaults(self, specs):
         """Add facts about targets and target compatibility."""
+        self.gen.h2("Default target")
+
+        platform = spack.platforms.host()
+        uarch = archspec.cpu.TARGETS.get(platform.default)
+
         self.gen.h2("Target compatibility")
 
-        # Add targets explicitly requested from specs
-        candidate_targets = []
-        for x in self.possible_graph.candidate_targets():
-            if all(
-                self.possible_graph.unreachable(pkg_name=pkg_name, when_spec=f"target={x}")
-                for pkg_name in self.pkgs
-            ):
-                tty.debug(f"[{__name__}] excluding target={x}, cause no package can use it")
-                continue
-            candidate_targets.append(x)
+        # Construct the list of targets which are compatible with the host
+        candidate_targets = [uarch] + uarch.ancestors
 
-        host_compatible = spack.config.CONFIG.get("concretizer:targets:host_compatible")
+        # Get configuration options
+        granularity = spack.config.get("concretizer:targets:granularity")
+        host_compatible = spack.config.get("concretizer:targets:host_compatible")
+
+        # Add targets which are not compatible with the current host
+        if not host_compatible:
+            additional_targets_in_family = sorted(
+                [
+                    t
+                    for t in archspec.cpu.TARGETS.values()
+                    if (t.family.name == uarch.family.name and t not in candidate_targets)
+                ],
+                key=lambda x: len(x.ancestors),
+                reverse=True,
+            )
+            candidate_targets += additional_targets_in_family
+
+        # Check if we want only generic architecture
+        if granularity == "generic":
+            candidate_targets = [t for t in candidate_targets if t.vendor == "generic"]
+
+        # Add targets explicitly requested from specs
         for spec in specs:
             if not spec.architecture or not spec.architecture.target:
                 continue
@@ -2426,8 +2444,6 @@ def target_defaults(self, specs):
                     if ancestor not in candidate_targets:
                         candidate_targets.append(ancestor)
 
-        platform = spack.platforms.host()
-        uarch = archspec.cpu.TARGETS.get(platform.default)
         best_targets = {uarch.family.name}
         for compiler_id, known_compiler in enumerate(self.possible_compilers):
             if not known_compiler.available:
@@ -2485,6 +2501,7 @@ def target_defaults(self, specs):
             self.gen.newline()
 
         self.default_targets = list(sorted(set(self.default_targets)))
+
         self.target_preferences()
 
     def virtual_providers(self):
@@ -2588,14 +2605,7 @@ def define_variant_values(self):
         # Tell the concretizer about possible values from specs seen in spec_clauses().
         # We might want to order these facts by pkg and name if we are debugging.
         for pkg_name, variant_def_id, value in self.variant_values_from_specs:
-            try:
-                vid = self.variant_ids_by_def_id[variant_def_id]
-            except KeyError:
-                tty.debug(
-                    f"[{__name__}] cannot retrieve id of the {value} variant from {pkg_name}"
-                )
-                continue
-
+            vid = self.variant_ids_by_def_id[variant_def_id]
             self.gen.fact(fn.pkg_fact(pkg_name, fn.variant_possible_value(vid, value)))
 
     def register_concrete_spec(self, spec, possible):
@@ -2666,7 +2676,7 @@ def setup(
         """
         check_packages_exist(specs)
 
-        node_counter = create_counter(specs, tests=self.tests, possible_graph=self.possible_graph)
+        node_counter = _create_counter(specs, tests=self.tests)
         self.possible_virtuals = node_counter.possible_virtuals()
         self.pkgs = node_counter.possible_dependencies()
         self.libcs = sorted(all_libcs())  # type: ignore[type-var]
@@ -2674,9 +2684,7 @@ def setup(
         # Fail if we already know an unreachable node is requested
         for spec in specs:
             missing_deps = [
-                str(d)
-                for d in spec.traverse()
-                if d.name not in self.pkgs and not spack.repo.PATH.is_virtual(d.name)
+                str(d) for d in spec.traverse() if d.name not in self.pkgs and not d.virtual
             ]
             if missing_deps:
                 raise spack.spec.InvalidDependencyError(spec.name, missing_deps)
@@ -2893,11 +2901,7 @@ def literal_specs(self, specs):
                     pkg_name = clause.args[1]
                     self.gen.fact(fn.mentioned_in_literal(trigger_id, root_name, pkg_name))
 
-            requirements.append(
-                fn.attr(
-                    "virtual_root" if spack.repo.PATH.is_virtual(spec.name) else "root", spec.name
-                )
-            )
+            requirements.append(fn.attr("virtual_root" if spec.virtual else "root", spec.name))
             cache[imposed_spec_key] = (effect_id, requirements)
             self.gen.fact(fn.pkg_fact(spec.name, fn.condition_effect(condition_id, effect_id)))
 
@@ -3485,7 +3489,7 @@ def external_spec_selected(self, node, idx):
         self._specs[node].extra_attributes = spec_info.get("extra_attributes", {})
 
         # If this is an extension, update the dependencies to include the extendee
-        package = spack.repo.PATH.get_pkg_class(self._specs[node].fullname)(self._specs[node])
+        package = self._specs[node].package_class(self._specs[node])
         extendee_spec = package.extendee_spec
 
         if extendee_spec:
@@ -4098,10 +4102,10 @@ def _check_input_and_extract_concrete_specs(specs):
         reusable = []
         for root in specs:
             for s in root.traverse():
+                if s.virtual:
+                    continue
                 if s.concrete:
                     reusable.append(s)
-                elif spack.repo.PATH.is_virtual(s.name):
-                    continue
                 spack.spec.Spec.ensure_valid_variants(s)
         return reusable
 

lib/spack/spack/solver/concretize.lp

@@ -265,7 +265,6 @@ error(100, "Cannot select a single version for virtual '{0}'", Virtual)
 % If we select a deprecated version, mark the package as deprecated
 attr("deprecated", node(ID, Package), Version) :-
      attr("version", node(ID, Package), Version),
-     not external(node(ID, Package)),
      pkg_fact(Package, deprecated_version(Version)).
 
 error(100, "Package '{0}' needs the deprecated version '{1}', and this is not allowed", Package, Version)

lib/spack/spack/solver/counter.py

@@ -0,0 +1,179 @@
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+import collections
+from typing import List, Set
+
+from llnl.util import lang
+
+import spack.deptypes as dt
+import spack.package_base
+import spack.repo
+import spack.spec
+
+PossibleDependencies = Set[str]
+
+
+class Counter:
+    """Computes the possible packages and the maximum number of duplicates
+    allowed for each of them.
+
+    Args:
+        specs: abstract specs to concretize
+        tests: if True, add test dependencies to the list of possible packages
+    """
+
+    def __init__(self, specs: List["spack.spec.Spec"], tests: bool) -> None:
+        runtime_pkgs = spack.repo.PATH.packages_with_tags("runtime")
+        runtime_virtuals = set()
+        for x in runtime_pkgs:
+            pkg_class = spack.repo.PATH.get_pkg_class(x)
+            runtime_virtuals.update(pkg_class.provided_virtual_names())
+
+        self.specs = specs + [spack.spec.Spec(x) for x in runtime_pkgs]
+
+        self.link_run_types: dt.DepFlag = dt.LINK | dt.RUN | dt.TEST
+        self.all_types: dt.DepFlag = dt.ALL
+        if not tests:
+            self.link_run_types = dt.LINK | dt.RUN
+            self.all_types = dt.LINK | dt.RUN | dt.BUILD
+
+        self._possible_dependencies: PossibleDependencies = set()
+        self._possible_virtuals: Set[str] = (
+            set(x.name for x in specs if x.virtual) | runtime_virtuals
+        )
+
+    def possible_dependencies(self) -> PossibleDependencies:
+        """Returns the list of possible dependencies"""
+        self.ensure_cache_values()
+        return self._possible_dependencies
+
+    def possible_virtuals(self) -> Set[str]:
+        """Returns the list of possible virtuals"""
+        self.ensure_cache_values()
+        return self._possible_virtuals
+
+    def ensure_cache_values(self) -> None:
+        """Ensure the cache values have been computed"""
+        if self._possible_dependencies:
+            return
+        self._compute_cache_values()
+
+    def possible_packages_facts(self, gen: "spack.solver.asp.PyclingoDriver", fn) -> None:
+        """Emit facts associated with the possible packages"""
+        raise NotImplementedError("must be implemented by derived classes")
+
+    def _compute_cache_values(self):
+        raise NotImplementedError("must be implemented by derived classes")
+
+
+class NoDuplicatesCounter(Counter):
+    def _compute_cache_values(self):
+        result = spack.package_base.possible_dependencies(
+            *self.specs, virtuals=self._possible_virtuals, depflag=self.all_types
+        )
+        self._possible_dependencies = set(result)
+
+    def possible_packages_facts(self, gen, fn):
+        gen.h2("Maximum number of nodes (packages)")
+        for package_name in sorted(self.possible_dependencies()):
+            gen.fact(fn.max_dupes(package_name, 1))
+        gen.newline()
+        gen.h2("Maximum number of nodes (virtual packages)")
+        for package_name in sorted(self.possible_virtuals()):
+            gen.fact(fn.max_dupes(package_name, 1))
+        gen.newline()
+        gen.h2("Possible package in link-run subDAG")
+        for name in sorted(self.possible_dependencies()):
+            gen.fact(fn.possible_in_link_run(name))
+        gen.newline()
+
+
+class MinimalDuplicatesCounter(NoDuplicatesCounter):
+    def __init__(self, specs, tests):
+        super().__init__(specs, tests)
+        self._link_run: PossibleDependencies = set()
+        self._direct_build: PossibleDependencies = set()
+        self._total_build: PossibleDependencies = set()
+        self._link_run_virtuals: Set[str] = set()
+
+    def _compute_cache_values(self):
+        self._link_run = set(
+            spack.package_base.possible_dependencies(
+                *self.specs, virtuals=self._possible_virtuals, depflag=self.link_run_types
+            )
+        )
+        self._link_run_virtuals.update(self._possible_virtuals)
+        for x in self._link_run:
+            build_dependencies = spack.repo.PATH.get_pkg_class(x).dependencies_of_type(dt.BUILD)
+            virtuals, reals = lang.stable_partition(
+                build_dependencies, spack.repo.PATH.is_virtual_safe
+            )
+
+            self._possible_virtuals.update(virtuals)
+            for virtual_dep in virtuals:
+                providers = spack.repo.PATH.providers_for(virtual_dep)
+                self._direct_build.update(str(x) for x in providers)
+
+            self._direct_build.update(reals)
+
+        self._total_build = set(
+            spack.package_base.possible_dependencies(
+                *self._direct_build, virtuals=self._possible_virtuals, depflag=self.all_types
+            )
+        )
+        self._possible_dependencies = set(self._link_run) | set(self._total_build)
+
+    def possible_packages_facts(self, gen, fn):
+        build_tools = spack.repo.PATH.packages_with_tags("build-tools")
+        gen.h2("Packages with at most a single node")
+        for package_name in sorted(self.possible_dependencies() - build_tools):
+            gen.fact(fn.max_dupes(package_name, 1))
+        gen.newline()
+
+        gen.h2("Packages with at multiple possible nodes (build-tools)")
+        for package_name in sorted(self.possible_dependencies() & build_tools):
+            gen.fact(fn.max_dupes(package_name, 2))
+            gen.fact(fn.multiple_unification_sets(package_name))
+        gen.newline()
+
+        gen.h2("Maximum number of nodes (virtual packages)")
+        for package_name in sorted(self.possible_virtuals()):
+            gen.fact(fn.max_dupes(package_name, 1))
+        gen.newline()
+
+        gen.h2("Possible package in link-run subDAG")
+        for name in sorted(self._link_run):
+            gen.fact(fn.possible_in_link_run(name))
+        gen.newline()
+
+
+class FullDuplicatesCounter(MinimalDuplicatesCounter):
+    def possible_packages_facts(self, gen, fn):
+        build_tools = spack.repo.PATH.packages_with_tags("build-tools")
+        counter = collections.Counter(
+            list(self._link_run) + list(self._total_build) + list(self._direct_build)
+        )
+        gen.h2("Maximum number of nodes")
+        for pkg, count in sorted(counter.items(), key=lambda x: (x[1], x[0])):
+            count = min(count, 2)
+            gen.fact(fn.max_dupes(pkg, count))
+        gen.newline()
+
+        gen.h2("Build unification sets ")
+        for name in sorted(self.possible_dependencies() & build_tools):
+            gen.fact(fn.multiple_unification_sets(name))
+        gen.newline()
+
+        gen.h2("Possible package in link-run subDAG")
+        for name in sorted(self._link_run):
+            gen.fact(fn.possible_in_link_run(name))
+        gen.newline()
+
+        counter = collections.Counter(
+            list(self._link_run_virtuals) + list(self._possible_virtuals)
+        )
+        gen.h2("Maximum number of virtual nodes")
+        for pkg, count in sorted(counter.items(), key=lambda x: (x[1], x[0])):
+            gen.fact(fn.max_dupes(pkg, count))
+        gen.newline()

lib/spack/spack/solver/input_analysis.py

@@ -1,526 +0,0 @@
-# Copyright Spack Project Developers. See COPYRIGHT file for details.
-#
-# SPDX-License-Identifier: (Apache-2.0 OR MIT)
-"""Classes to analyze the input of a solve, and provide information to set up the ASP problem"""
-import collections
-from typing import Dict, List, NamedTuple, Set, Tuple, Union
-
-import archspec.cpu
-
-from llnl.util import lang, tty
-
-import spack.binary_distribution
-import spack.config
-import spack.deptypes as dt
-import spack.platforms
-import spack.repo
-import spack.spec
-import spack.store
-from spack.error import SpackError
-
-RUNTIME_TAG = "runtime"
-
-
-class PossibleGraph(NamedTuple):
-    real_pkgs: Set[str]
-    virtuals: Set[str]
-    edges: Dict[str, Set[str]]
-
-
-class PossibleDependencyGraph:
-    """Returns information needed to set up an ASP problem"""
-
-    def unreachable(self, *, pkg_name: str, when_spec: spack.spec.Spec) -> bool:
-        """Returns true if the context can determine that the condition cannot ever
-        be met on pkg_name.
-        """
-        raise NotImplementedError
-
-    def candidate_targets(self) -> List[archspec.cpu.Microarchitecture]:
-        """Returns a list of targets that are candidate for concretization"""
-        raise NotImplementedError
-
-    def possible_dependencies(
-        self,
-        *specs: Union[spack.spec.Spec, str],
-        allowed_deps: dt.DepFlag,
-        transitive: bool = True,
-        strict_depflag: bool = False,
-        expand_virtuals: bool = True,
-    ) -> PossibleGraph:
-        """Returns the set of possible dependencies, and the set of possible virtuals.
-
-        Both sets always include runtime packages, which may be injected by compilers.
-
-        Args:
-            transitive: return transitive dependencies if True, only direct dependencies if False
-            allowed_deps: dependency types to consider
-            strict_depflag: if True, only the specific dep type is considered, if False any
-                deptype that intersects with allowed deptype is considered
-            expand_virtuals: expand virtual dependencies into all possible implementations
-        """
-        raise NotImplementedError
-
-
-class NoStaticAnalysis(PossibleDependencyGraph):
-    """Implementation that tries to minimize the setup time (i.e. defaults to give fast
-    answers), rather than trying to reduce the ASP problem size with more complex analysis.
-    """
-
-    def __init__(self, *, configuration: spack.config.Configuration, repo: spack.repo.RepoPath):
-        self.configuration = configuration
-        self.repo = repo
-        self.runtime_pkgs = set(self.repo.packages_with_tags(RUNTIME_TAG))
-        self.runtime_virtuals = set()
-        self._platform_condition = spack.spec.Spec(
-            f"platform={spack.platforms.host()} target={archspec.cpu.host().family}:"
-        )
-        for x in self.runtime_pkgs:
-            pkg_class = self.repo.get_pkg_class(x)
-            self.runtime_virtuals.update(pkg_class.provided_virtual_names())
-
-        try:
-            self.libc_pkgs = [x.name for x in self.providers_for("libc")]
-        except spack.repo.UnknownPackageError:
-            self.libc_pkgs = []
-
-    def is_virtual(self, name: str) -> bool:
-        return self.repo.is_virtual(name)
-
-    @lang.memoized
-    def is_allowed_on_this_platform(self, *, pkg_name: str) -> bool:
-        """Returns true if a package is allowed on the current host"""
-        pkg_cls = self.repo.get_pkg_class(pkg_name)
-        for when_spec, conditions in pkg_cls.requirements.items():
-            if not when_spec.intersects(self._platform_condition):
-                continue
-            for requirements, _, _ in conditions:
-                if not any(x.intersects(self._platform_condition) for x in requirements):
-                    tty.debug(f"[{__name__}] {pkg_name} is not for this platform")
-                    return False
-        return True
-
-    def providers_for(self, virtual_str: str) -> List[spack.spec.Spec]:
-        """Returns a list of possible providers for the virtual string in input."""
-        return self.repo.providers_for(virtual_str)
-
-    def can_be_installed(self, *, pkg_name) -> bool:
-        """Returns True if a package can be installed, False otherwise."""
-        return True
-
-    def unreachable(self, *, pkg_name: str, when_spec: spack.spec.Spec) -> bool:
-        """Returns true if the context can determine that the condition cannot ever
-        be met on pkg_name.
-        """
-        return False
-
-    def candidate_targets(self) -> List[archspec.cpu.Microarchitecture]:
-        """Returns a list of targets that are candidate for concretization"""
-        platform = spack.platforms.host()
-        default_target = archspec.cpu.TARGETS[platform.default]
-
-        # Construct the list of targets which are compatible with the host
-        candidate_targets = [default_target] + default_target.ancestors
-        granularity = self.configuration.get("concretizer:targets:granularity")
-        host_compatible = self.configuration.get("concretizer:targets:host_compatible")
-
-        # Add targets which are not compatible with the current host
-        if not host_compatible:
-            additional_targets_in_family = sorted(
-                [
-                    t
-                    for t in archspec.cpu.TARGETS.values()
-                    if (t.family.name == default_target.family.name and t not in candidate_targets)
-                ],
-                key=lambda x: len(x.ancestors),
-                reverse=True,
-            )
-            candidate_targets += additional_targets_in_family
-
-        # Check if we want only generic architecture
-        if granularity == "generic":
-            candidate_targets = [t for t in candidate_targets if t.vendor == "generic"]
-
-        return candidate_targets
-
-    def possible_dependencies(
-        self,
-        *specs: Union[spack.spec.Spec, str],
-        allowed_deps: dt.DepFlag,
-        transitive: bool = True,
-        strict_depflag: bool = False,
-        expand_virtuals: bool = True,
-    ) -> PossibleGraph:
-        stack = [x for x in self._package_list(specs)]
-        virtuals: Set[str] = set()
-        edges: Dict[str, Set[str]] = {}
-
-        while stack:
-            pkg_name = stack.pop()
-
-            if pkg_name in edges:
-                continue
-
-            edges[pkg_name] = set()
-
-            # Since libc is not buildable, there is no need to extend the
-            # search space with libc dependencies.
-            if pkg_name in self.libc_pkgs:
-                continue
-
-            pkg_cls = self.repo.get_pkg_class(pkg_name=pkg_name)
-            for name, conditions in pkg_cls.dependencies_by_name(when=True).items():
-                if all(self.unreachable(pkg_name=pkg_name, when_spec=x) for x in conditions):
-                    tty.debug(
-                        f"[{__name__}] Not adding {name} as a dep of {pkg_name}, because "
-                        f"conditions cannot be met"
-                    )
-                    continue
-
-                if not self._has_deptypes(
-                    conditions, allowed_deps=allowed_deps, strict=strict_depflag
-                ):
-                    continue
-
-                if name in virtuals:
-                    continue
-
-                dep_names = set()
-                if self.is_virtual(name):
-                    virtuals.add(name)
-                    if expand_virtuals:
-                        providers = self.providers_for(name)
-                        dep_names = {spec.name for spec in providers}
-                else:
-                    dep_names = {name}
-
-                edges[pkg_name].update(dep_names)
-
-                if not transitive:
-                    continue
-
-                for dep_name in dep_names:
-                    if dep_name in edges:
-                        continue
-
-                    if not self._is_possible(pkg_name=dep_name):
-                        continue
-
-                    stack.append(dep_name)
-
-        real_packages = set(edges)
-        if not transitive:
-            # We exit early, so add children from the edges information
-            for root, children in edges.items():
-                real_packages.update(x for x in children if self._is_possible(pkg_name=x))
-
-        virtuals.update(self.runtime_virtuals)
-        real_packages = real_packages | self.runtime_pkgs
-        return PossibleGraph(real_pkgs=real_packages, virtuals=virtuals, edges=edges)
-
-    def _package_list(self, specs: Tuple[Union[spack.spec.Spec, str], ...]) -> List[str]:
-        stack = []
-        for current_spec in specs:
-            if isinstance(current_spec, str):
-                current_spec = spack.spec.Spec(current_spec)
-
-            if self.repo.is_virtual(current_spec.name):
-                stack.extend([p.name for p in self.providers_for(current_spec.name)])
-                continue
-
-            stack.append(current_spec.name)
-        return sorted(set(stack))
-
-    def _has_deptypes(self, dependencies, *, allowed_deps: dt.DepFlag, strict: bool) -> bool:
-        if strict is True:
-            return any(
-                dep.depflag == allowed_deps for deplist in dependencies.values() for dep in deplist
-            )
-        return any(
-            dep.depflag & allowed_deps for deplist in dependencies.values() for dep in deplist
-        )
-
-    def _is_possible(self, *, pkg_name):
-        try:
-            return self.is_allowed_on_this_platform(pkg_name=pkg_name) and self.can_be_installed(
-                pkg_name=pkg_name
-            )
-        except spack.repo.UnknownPackageError:
-            return False
-
-
-class StaticAnalysis(NoStaticAnalysis):
-    """Performs some static analysis of the configuration, store, etc. to provide more precise
-    answers on whether some packages can be installed, or used as a provider.
-
-    It increases the setup time, but might decrease the grounding and solve time considerably,
-    especially when requirements restrict the possible choices for providers.
-    """
-
-    def __init__(
-        self,
-        *,
-        configuration: spack.config.Configuration,
-        repo: spack.repo.RepoPath,
-        store: spack.store.Store,
-        binary_index: spack.binary_distribution.BinaryCacheIndex,
-    ):
-        super().__init__(configuration=configuration, repo=repo)
-        self.store = store
-        self.binary_index = binary_index
-
-    @lang.memoized
-    def providers_for(self, virtual_str: str) -> List[spack.spec.Spec]:
-        candidates = super().providers_for(virtual_str)
-        result = []
-        for spec in candidates:
-            if not self._is_provider_candidate(pkg_name=spec.name, virtual=virtual_str):
-                continue
-            result.append(spec)
-        return result
-
-    @lang.memoized
-    def buildcache_specs(self) -> List[spack.spec.Spec]:
-        self.binary_index.update()
-        return self.binary_index.get_all_built_specs()
-
-    @lang.memoized
-    def can_be_installed(self, *, pkg_name) -> bool:
-        if self.configuration.get(f"packages:{pkg_name}:buildable", True):
-            return True
-
-        if self.configuration.get(f"packages:{pkg_name}:externals", []):
-            return True
-
-        reuse = self.configuration.get("concretizer:reuse")
-        if reuse is not False and self.store.db.query(pkg_name):
-            return True
-
-        if reuse is not False and any(x.name == pkg_name for x in self.buildcache_specs()):
-            return True
-
-        tty.debug(f"[{__name__}] {pkg_name} cannot be installed")
-        return False
-
-    @lang.memoized
-    def _is_provider_candidate(self, *, pkg_name: str, virtual: str) -> bool:
-        if not self.is_allowed_on_this_platform(pkg_name=pkg_name):
-            return False
-
-        if not self.can_be_installed(pkg_name=pkg_name):
-            return False
-
-        virtual_spec = spack.spec.Spec(virtual)
-        if self.unreachable(pkg_name=virtual_spec.name, when_spec=pkg_name):
-            tty.debug(f"[{__name__}] {pkg_name} cannot be a provider for {virtual}")
-            return False
-
-        return True
-
-    @lang.memoized
-    def unreachable(self, *, pkg_name: str, when_spec: spack.spec.Spec) -> bool:
-        """Returns true if the context can determine that the condition cannot ever
-        be met on pkg_name.
-        """
-        candidates = self.configuration.get(f"packages:{pkg_name}:require", [])
-        if not candidates and pkg_name != "all":
-            return self.unreachable(pkg_name="all", when_spec=when_spec)
-
-        if not candidates:
-            return False
-
-        if isinstance(candidates, str):
-            candidates = [candidates]
-
-        union_requirement = spack.spec.Spec()
-        for c in candidates:
-            if not isinstance(c, str):
-                continue
-            try:
-                union_requirement.constrain(c)
-            except SpackError:
-                # Less optimized, but shouldn't fail
-                pass
-
-        if not union_requirement.intersects(when_spec):
-            return True
-
-        return False
-
-
-def create_graph_analyzer() -> PossibleDependencyGraph:
-    static_analysis = spack.config.CONFIG.get("concretizer:static_analysis", False)
-    if static_analysis:
-        return StaticAnalysis(
-            configuration=spack.config.CONFIG,
-            repo=spack.repo.PATH,
-            store=spack.store.STORE,
-            binary_index=spack.binary_distribution.BINARY_INDEX,
-        )
-    return NoStaticAnalysis(configuration=spack.config.CONFIG, repo=spack.repo.PATH)
-
-
-class Counter:
-    """Computes the possible packages and the maximum number of duplicates
-    allowed for each of them.
-
-    Args:
-        specs: abstract specs to concretize
-        tests: if True, add test dependencies to the list of possible packages
-    """
-
-    def __init__(
-        self, specs: List["spack.spec.Spec"], tests: bool, possible_graph: PossibleDependencyGraph
-    ) -> None:
-        self.possible_graph = possible_graph
-        self.specs = specs
-        self.link_run_types: dt.DepFlag = dt.LINK | dt.RUN | dt.TEST
-        self.all_types: dt.DepFlag = dt.ALL
-        if not tests:
-            self.link_run_types = dt.LINK | dt.RUN
-            self.all_types = dt.LINK | dt.RUN | dt.BUILD
-
-        self._possible_dependencies: Set[str] = set()
-        self._possible_virtuals: Set[str] = {
-            x.name for x in specs if spack.repo.PATH.is_virtual(x.name)
-        }
-
-    def possible_dependencies(self) -> Set[str]:
-        """Returns the list of possible dependencies"""
-        self.ensure_cache_values()
-        return self._possible_dependencies
-
-    def possible_virtuals(self) -> Set[str]:
-        """Returns the list of possible virtuals"""
-        self.ensure_cache_values()
-        return self._possible_virtuals
-
-    def ensure_cache_values(self) -> None:
-        """Ensure the cache values have been computed"""
-        if self._possible_dependencies:
-            return
-        self._compute_cache_values()
-
-    def possible_packages_facts(self, gen: "spack.solver.asp.ProblemInstanceBuilder", fn) -> None:
-        """Emit facts associated with the possible packages"""
-        raise NotImplementedError("must be implemented by derived classes")
-
-    def _compute_cache_values(self) -> None:
-        raise NotImplementedError("must be implemented by derived classes")
-
-
-class NoDuplicatesCounter(Counter):
-    def _compute_cache_values(self) -> None:
-        self._possible_dependencies, virtuals, _ = self.possible_graph.possible_dependencies(
-            *self.specs, allowed_deps=self.all_types
-        )
-        self._possible_virtuals.update(virtuals)
-
-    def possible_packages_facts(self, gen: "spack.solver.asp.ProblemInstanceBuilder", fn) -> None:
-        gen.h2("Maximum number of nodes (packages)")
-        for package_name in sorted(self.possible_dependencies()):
-            gen.fact(fn.max_dupes(package_name, 1))
-        gen.newline()
-        gen.h2("Maximum number of nodes (virtual packages)")
-        for package_name in sorted(self.possible_virtuals()):
-            gen.fact(fn.max_dupes(package_name, 1))
-        gen.newline()
-        gen.h2("Possible package in link-run subDAG")
-        for name in sorted(self.possible_dependencies()):
-            gen.fact(fn.possible_in_link_run(name))
-        gen.newline()
-
-
-class MinimalDuplicatesCounter(NoDuplicatesCounter):
-    def __init__(
-        self, specs: List["spack.spec.Spec"], tests: bool, possible_graph: PossibleDependencyGraph
-    ) -> None:
-        super().__init__(specs, tests, possible_graph)
-        self._link_run: Set[str] = set()
-        self._direct_build: Set[str] = set()
-        self._total_build: Set[str] = set()
-        self._link_run_virtuals: Set[str] = set()
-
-    def _compute_cache_values(self) -> None:
-        self._link_run, virtuals, _ = self.possible_graph.possible_dependencies(
-            *self.specs, allowed_deps=self.link_run_types
-        )
-        self._possible_virtuals.update(virtuals)
-        self._link_run_virtuals.update(virtuals)
-        for x in self._link_run:
-            reals, virtuals, _ = self.possible_graph.possible_dependencies(
-                x, allowed_deps=dt.BUILD, transitive=False, strict_depflag=True
-            )
-            self._possible_virtuals.update(virtuals)
-            self._direct_build.update(reals)
-
-        self._total_build, virtuals, _ = self.possible_graph.possible_dependencies(
-            *self._direct_build, allowed_deps=self.all_types
-        )
-        self._possible_virtuals.update(virtuals)
-        self._possible_dependencies = set(self._link_run) | set(self._total_build)
-
-    def possible_packages_facts(self, gen, fn):
-        build_tools = spack.repo.PATH.packages_with_tags("build-tools")
-        gen.h2("Packages with at most a single node")
-        for package_name in sorted(self.possible_dependencies() - build_tools):
-            gen.fact(fn.max_dupes(package_name, 1))
-        gen.newline()
-
-        gen.h2("Packages with at multiple possible nodes (build-tools)")
-        for package_name in sorted(self.possible_dependencies() & build_tools):
-            gen.fact(fn.max_dupes(package_name, 2))
-            gen.fact(fn.multiple_unification_sets(package_name))
-        gen.newline()
-
-        gen.h2("Maximum number of nodes (virtual packages)")
-        for package_name in sorted(self.possible_virtuals()):
-            gen.fact(fn.max_dupes(package_name, 1))
-        gen.newline()
-
-        gen.h2("Possible package in link-run subDAG")
-        for name in sorted(self._link_run):
-            gen.fact(fn.possible_in_link_run(name))
-        gen.newline()
-
-
-class FullDuplicatesCounter(MinimalDuplicatesCounter):
-    def possible_packages_facts(self, gen, fn):
-        build_tools = spack.repo.PATH.packages_with_tags("build-tools")
-        counter = collections.Counter(
-            list(self._link_run) + list(self._total_build) + list(self._direct_build)
-        )
-        gen.h2("Maximum number of nodes")
-        for pkg, count in sorted(counter.items(), key=lambda x: (x[1], x[0])):
-            count = min(count, 2)
-            gen.fact(fn.max_dupes(pkg, count))
-        gen.newline()
-
-        gen.h2("Build unification sets ")
-        for name in sorted(self.possible_dependencies() & build_tools):
-            gen.fact(fn.multiple_unification_sets(name))
-        gen.newline()
-
-        gen.h2("Possible package in link-run subDAG")
-        for name in sorted(self._link_run):
-            gen.fact(fn.possible_in_link_run(name))
-        gen.newline()
-
-        counter = collections.Counter(
-            list(self._link_run_virtuals) + list(self._possible_virtuals)
-        )
-        gen.h2("Maximum number of virtual nodes")
-        for pkg, count in sorted(counter.items(), key=lambda x: (x[1], x[0])):
-            gen.fact(fn.max_dupes(pkg, count))
-        gen.newline()
-
-
-def create_counter(
-    specs: List[spack.spec.Spec], tests: bool, possible_graph: PossibleDependencyGraph
-) -> Counter:
-    strategy = spack.config.CONFIG.get("concretizer:duplicates:strategy", "none")
-    if strategy == "full":
-        return FullDuplicatesCounter(specs, tests=tests, possible_graph=possible_graph)
-    if strategy == "minimal":
-        return MinimalDuplicatesCounter(specs, tests=tests, possible_graph=possible_graph)
-    return NoDuplicatesCounter(specs, tests=tests, possible_graph=possible_graph)

lib/spack/spack/spec.py

@@ -230,7 +230,7 @@ def ensure_modern_format_string(fmt: str) -> None:
 def _make_microarchitecture(name: str) -> archspec.cpu.Microarchitecture:
     if isinstance(name, archspec.cpu.Microarchitecture):
         return name
-    return archspec.cpu.TARGETS.get(name, archspec.cpu.generic_microarchitecture(name))
+    return archspec.cpu.TARGETS.get(name) or archspec.cpu.generic_microarchitecture(name)
 
 
 @lang.lazy_lexicographic_ordering
@@ -238,14 +238,23 @@ class ArchSpec:
     """Aggregate the target platform, the operating system and the target microarchitecture."""
 
     @staticmethod
-    def default_arch():
-        """Return the default architecture"""
+    def _return_arch(os_tag, target_tag):
         platform = spack.platforms.host()
-        default_os = platform.default_operating_system()
-        default_target = platform.default_target()
+        default_os = platform.operating_system(os_tag)
+        default_target = platform.target(target_tag)
         arch_tuple = str(platform), str(default_os), str(default_target)
         return ArchSpec(arch_tuple)
 
+    @staticmethod
+    def default_arch():
+        """Return the default architecture"""
+        return ArchSpec._return_arch("default_os", "default_target")
+
+    @staticmethod
+    def frontend_arch():
+        """Return the frontend architecture"""
+        return ArchSpec._return_arch("frontend", "frontend")
+
     __slots__ = "_platform", "_os", "_target"
 
     def __init__(self, spec_or_platform_tuple=(None, None, None)):
@@ -458,10 +467,10 @@ def _target_constrain(self, other: "ArchSpec") -> bool:
         if not other._target_satisfies(self, strict=False):
             raise UnsatisfiableArchitectureSpecError(self, other)
 
-        if self.target_concrete:
+        if self._target_concrete:
             return False
 
-        elif other.target_concrete:
+        elif other._target_concrete:
             self.target = other.target
             return True
 
@@ -476,8 +485,8 @@ def _target_constrain(self, other: "ArchSpec") -> bool:
         self.target = intersection_target
         return True
 
-    def _target_intersection(self, other):
-        results = []
+    def _target_intersection(self, other: "ArchSpec") -> List[str]:
+        results: List[str] = []
 
         if not self.target or not other.target:
             return results
@@ -584,23 +593,23 @@ def constrain(self, other: "ArchSpec") -> bool:
 
         return constrained
 
-    def copy(self):
+    def copy(self) -> "ArchSpec":
         """Copy the current instance and returns the clone."""
         return ArchSpec(self)
 
     @property
     def concrete(self):
         """True if the spec is concrete, False otherwise"""
-        return self.platform and self.os and self.target and self.target_concrete
+        return self.platform and self.os and self.target and self._target_concrete
 
     @property
-    def target_concrete(self):
+    def _target_concrete(self) -> bool:
         """True if the target is not a range or list."""
         return (
             self.target is not None and ":" not in str(self.target) and "," not in str(self.target)
         )
 
-    def to_dict(self):
+    def to_dict(self) -> dict:
         # Generic targets represent either an architecture family (like x86_64)
         # or a custom micro-architecture
         if self.target.vendor == "generic":
@@ -612,7 +621,7 @@ def to_dict(self):
         return {"arch": {"platform": self.platform, "platform_os": self.os, "target": target_data}}
 
     @staticmethod
-    def from_dict(d):
+    def from_dict(d: dict) -> "ArchSpec":
         """Import an ArchSpec from raw YAML/JSON data"""
         arch = d["arch"]
         target_name = arch["target"]
@@ -622,13 +631,12 @@ def from_dict(d):
         return ArchSpec((arch["platform"], arch["platform_os"], target))
 
     def __str__(self):
-        return "%s-%s-%s" % (self.platform, self.os, self.target)
+        return f"{self.platform}-{self.os}-{self.target}"
 
     def __repr__(self):
-        fmt = "ArchSpec(({0.platform!r}, {0.os!r}, {1!r}))"
-        return fmt.format(self, str(self.target))
+        return f"ArchSpec(({self.platform!r}, {self.os!r}, {str(self.target)!r}))"
 
-    def __contains__(self, string):
+    def __contains__(self, string) -> bool:
         return string in str(self) or string in self.target
 
 
@@ -1337,20 +1345,14 @@ class SpecBuildInterface(lang.ObjectWrapper):
         "command", default_handler=_command_default_handler, _indirect=True
     )
 
-    def __init__(
-        self,
-        spec: "Spec",
-        name: str,
-        query_parameters: List[str],
-        _parent: "Spec",
-        is_virtual: bool,
-    ):
+    def __init__(self, spec: "Spec", name: str, query_parameters: List[str], _parent: "Spec"):
         super().__init__(spec)
         # Adding new attributes goes after super() call since the ObjectWrapper
         # resets __dict__ to behave like the passed object
         original_spec = getattr(spec, "wrapped_obj", spec)
         self.wrapped_obj = original_spec
-        self.token = original_spec, name, query_parameters, _parent, is_virtual
+        self.token = original_spec, name, query_parameters, _parent
+        is_virtual = spack.repo.PATH.is_virtual(name)
         self.last_query = QueryState(
             name=name, extra_parameters=query_parameters, isvirtual=is_virtual
         )
@@ -1533,8 +1535,9 @@ def __init__(self, spec_like=None, *, external_path=None, external_modules=None)
         self._external_path = external_path
         self.external_modules = Spec._format_module_list(external_modules)
 
-        # This attribute is used to store custom information for external specs.
-        self.extra_attributes: dict = {}
+        # This attribute is used to store custom information for
+        # external specs. None signal that it was not set yet.
+        self.extra_attributes = None
 
         # This attribute holds the original build copy of the spec if it is
         # deployed differently than it was built. None signals that the spec
@@ -1911,22 +1914,10 @@ def package_class(self):
         """Internal package call gets only the class object for a package.
         Use this to just get package metadata.
         """
-        warnings.warn(
-            "`Spec.package_class` is deprecated and will be removed in version 1.0.0. Use "
-            "`spack.repo.PATH.get_pkg_class(spec.fullname) instead.",
-            category=spack.error.SpackAPIWarning,
-            stacklevel=2,
-        )
         return spack.repo.PATH.get_pkg_class(self.fullname)
 
     @property
     def virtual(self):
-        warnings.warn(
-            "`Spec.virtual` is deprecated and will be removed in version 1.0.0. Use "
-            "`spack.repo.PATH.is_virtual(spec.name)` instead.",
-            category=spack.error.SpackAPIWarning,
-            stacklevel=2,
-        )
         return spack.repo.PATH.is_virtual(self.name)
 
     @property
@@ -2368,10 +2359,15 @@ def to_node_dict(self, hash=ht.dag_hash):
             )
 
         if self.external:
+            if self.extra_attributes:
+                extra_attributes = syaml.sorted_dict(self.extra_attributes)
+            else:
+                extra_attributes = None
+
             d["external"] = {
                 "path": self.external_path,
-                "module": self.external_modules or None,
-                "extra_attributes": syaml.sorted_dict(self.extra_attributes),
+                "module": self.external_modules,
+                "extra_attributes": extra_attributes,
             }
 
         if not self._concrete:
@@ -2826,6 +2822,24 @@ def from_detection(
         s.extra_attributes = extra_attributes
         return s
 
+    def validate_detection(self):
+        """Validate the detection of an external spec.
+
+        This method is used as part of Spack's detection protocol, and is
+        not meant for client code use.
+        """
+        # Assert that _extra_attributes is a Mapping and not None,
+        # which likely means the spec was created with Spec.from_detection
+        msg = 'cannot validate "{0}" since it was not created ' "using Spec.from_detection".format(
+            self
+        )
+        assert isinstance(self.extra_attributes, collections.abc.Mapping), msg
+
+        # Validate the spec calling a package specific method
+        pkg_cls = spack.repo.PATH.get_pkg_class(self.name)
+        validate_fn = getattr(pkg_cls, "validate_detected_spec", lambda x, y: None)
+        validate_fn(self, self.extra_attributes)
+
     def _patches_assigned(self):
         """Whether patches have been assigned to this spec by the concretizer."""
         # FIXME: _patches_in_order_of_appearance is attached after concretization
@@ -2864,7 +2878,7 @@ def inject_patches_variant(root):
 
             # Add any patches from the package to the spec.
             patches = set()
-            for cond, patch_list in spack.repo.PATH.get_pkg_class(s.fullname).patches.items():
+            for cond, patch_list in s.package_class.patches.items():
                 if s.satisfies(cond):
                     for patch in patch_list:
                         patches.add(patch)
@@ -2877,7 +2891,7 @@ def inject_patches_variant(root):
             if dspec.spec.concrete:
                 continue
 
-            pkg_deps = spack.repo.PATH.get_pkg_class(dspec.parent.fullname).dependencies
+            pkg_deps = dspec.parent.package_class.dependencies
 
             patches = []
             for cond, deps_by_name in pkg_deps.items():
@@ -3084,7 +3098,7 @@ def validate_or_raise(self):
         # FIXME: raise just the first one encountered
         for spec in self.traverse():
             # raise an UnknownPackageError if the spec's package isn't real.
-            if spec.name and not spack.repo.PATH.is_virtual(spec.name):
+            if (not spec.virtual) and spec.name:
                 spack.repo.PATH.get_pkg_class(spec.fullname)
 
             # validate compiler in addition to the package name.
@@ -3093,7 +3107,7 @@ def validate_or_raise(self):
                     raise UnsupportedCompilerError(spec.compiler.name)
 
             # Ensure correctness of variants (if the spec is not virtual)
-            if not spack.repo.PATH.is_virtual(spec.name):
+            if not spec.virtual:
                 Spec.ensure_valid_variants(spec)
                 substitute_abstract_variants(spec)
 
@@ -3111,7 +3125,7 @@ def ensure_valid_variants(spec):
         if spec.concrete:
             return
 
-        pkg_cls = spack.repo.PATH.get_pkg_class(spec.fullname)
+        pkg_cls = spec.package_class
         pkg_variants = pkg_cls.variant_names()
         # reserved names are variants that may be set on any package
         # but are not necessarily recorded by the package's class
@@ -3328,9 +3342,7 @@ def intersects(self, other: Union[str, "Spec"], deps: bool = True) -> bool:
 
         # If the names are different, we need to consider virtuals
         if self.name != other.name and self.name and other.name:
-            self_virtual = spack.repo.PATH.is_virtual(self.name)
-            other_virtual = spack.repo.PATH.is_virtual(other.name)
-            if self_virtual and other_virtual:
+            if self.virtual and other.virtual:
                 # Two virtual specs intersect only if there are providers for both
                 lhs = spack.repo.PATH.providers_for(str(self))
                 rhs = spack.repo.PATH.providers_for(str(other))
@@ -3338,8 +3350,8 @@ def intersects(self, other: Union[str, "Spec"], deps: bool = True) -> bool:
                 return bool(intersection)
 
             # A provider can satisfy a virtual dependency.
-            elif self_virtual or other_virtual:
-                virtual_spec, non_virtual_spec = (self, other) if self_virtual else (other, self)
+            elif self.virtual or other.virtual:
+                virtual_spec, non_virtual_spec = (self, other) if self.virtual else (other, self)
                 try:
                     # Here we might get an abstract spec
                     pkg_cls = spack.repo.PATH.get_pkg_class(non_virtual_spec.fullname)
@@ -3444,9 +3456,7 @@ def satisfies(self, other: Union[str, "Spec"], deps: bool = True) -> bool:
         # If the names are different, we need to consider virtuals
         if self.name != other.name and self.name and other.name:
             # A concrete provider can satisfy a virtual dependency.
-            if not spack.repo.PATH.is_virtual(self.name) and spack.repo.PATH.is_virtual(
-                other.name
-            ):
+            if not self.virtual and other.virtual:
                 try:
                     # Here we might get an abstract spec
                     pkg_cls = spack.repo.PATH.get_pkg_class(self.fullname)
@@ -3514,7 +3524,7 @@ def satisfies(self, other: Union[str, "Spec"], deps: bool = True) -> bool:
         lhs_edges: Dict[str, Set[DependencySpec]] = collections.defaultdict(set)
         for rhs_edge in other.traverse_edges(root=False, cover="edges"):
             # If we are checking for ^mpi we need to verify if there is any edge
-            if spack.repo.PATH.is_virtual(rhs_edge.spec.name):
+            if rhs_edge.spec.virtual:
                 rhs_edge.update_virtuals(virtuals=(rhs_edge.spec.name,))
 
             if not rhs_edge.virtuals:
@@ -3560,7 +3570,7 @@ def satisfies(self, other: Union[str, "Spec"], deps: bool = True) -> bool:
 
     def virtual_dependencies(self):
         """Return list of any virtual deps in this spec."""
-        return [spec for spec in self.traverse() if spack.repo.PATH.is_virtual(spec.name)]
+        return [spec for spec in self.traverse() if spec.virtual]
 
     @property  # type: ignore[misc] # decorated prop not supported in mypy
     def patches(self):
@@ -3760,16 +3770,21 @@ def __getitem__(self, name: str):
         # Consider runtime dependencies and direct build/test deps before transitive dependencies,
         # and prefer matches closest to the root.
         try:
-            edge = next((e for e in order() if e.spec.name == name or name in e.virtuals))
+            child: Spec = next(
+                e.spec
+                for e in itertools.chain(
+                    (e for e in order() if e.spec.name == name or name in e.virtuals),
+                    # for historical reasons
+                    (e for e in order() if e.spec.concrete and e.spec.package.provides(name)),
+                )
+            )
         except StopIteration:
             raise KeyError(f"No spec with name {name} in {self}")
 
         if self._concrete:
-            return SpecBuildInterface(
-                edge.spec, name, query_parameters, _parent=self, is_virtual=name in edge.virtuals
-            )
+            return SpecBuildInterface(child, name, query_parameters, _parent=self)
 
-        return edge.spec
+        return child
 
     def __contains__(self, spec):
         """True if this spec or some dependency satisfies the spec.
@@ -3854,13 +3869,6 @@ def _cmp_iter(self):
         for item in self._cmp_node():
             yield item
 
-        # If there is ever a breaking change to hash computation, whether accidental or purposeful,
-        # two specs can be identical modulo DAG hash, depending on what time they were concretized
-        # From the perspective of many operation in Spack (database, build cache, etc) a different
-        # DAG hash means a different spec. Here we ensure that two otherwise identical specs, one
-        # serialized before the hash change and one after, are considered different.
-        yield self.dag_hash() if self.concrete else None
-
         # This needs to be in _cmp_iter so that no specs with different process hashes
         # are considered the same by `__hash__` or `__eq__`.
         #
@@ -4704,7 +4712,7 @@ def concrete(self):
             bool: True or False
         """
         return self.spec._concrete or all(
-            v in self for v in spack.repo.PATH.get_pkg_class(self.spec.fullname).variant_names()
+            v in self for v in self.spec.package_class.variant_names()
         )
 
     def copy(self) -> "VariantMap":
@@ -4726,10 +4734,7 @@ def __str__(self):
         bool_keys = []
         kv_keys = []
         for key in sorted_keys:
-            if isinstance(self[key].value, bool):
-                bool_keys.append(key)
-            else:
-                kv_keys.append(key)
+            bool_keys.append(key) if isinstance(self[key].value, bool) else kv_keys.append(key)
 
         # add spaces before and after key/value variants.
         string = io.StringIO()
@@ -4764,14 +4769,14 @@ def substitute_abstract_variants(spec: Spec):
         elif name in vt.reserved_names:
             continue
 
-        variant_defs = spack.repo.PATH.get_pkg_class(spec.fullname).variant_definitions(name)
+        variant_defs = spec.package_class.variant_definitions(name)
         valid_defs = []
         for when, vdef in variant_defs:
             if when.intersects(spec):
                 valid_defs.append(vdef)
 
         if not valid_defs:
-            if name not in spack.repo.PATH.get_pkg_class(spec.fullname).variant_names():
+            if name not in spec.package_class.variant_names():
                 unknown.append(name)
             else:
                 whens = [str(when) for when, _ in variant_defs]
@@ -4843,9 +4848,7 @@ def reconstruct_virtuals_on_edges(spec):
     possible_virtuals = set()
     for node in spec.traverse():
         try:
-            possible_virtuals.update(
-                {x for x in node.package.dependencies if spack.repo.PATH.is_virtual(x)}
-            )
+            possible_virtuals.update({x for x in node.package.dependencies if Spec(x).virtual})
         except Exception as e:
             warnings.warn(f"cannot reconstruct virtual dependencies on package {node.name}: {e}")
             continue
@@ -4910,7 +4913,7 @@ def from_node_dict(cls, node):
                 spec.external_modules = node["external"]["module"]
                 if spec.external_modules is False:
                     spec.external_modules = None
-                spec.extra_attributes = node["external"].get("extra_attributes") or {}
+                spec.extra_attributes = node["external"].get("extra_attributes", {})
 
         # specs read in are concrete unless marked abstract
         if node.get("concrete", True):
@@ -5187,10 +5190,12 @@ def get_host_environment_metadata() -> Dict[str, str]:
 
 
 def get_host_environment() -> Dict[str, Any]:
-    """Returns a dictionary with host information (not including the os.environ)."""
+    """Return a dictionary (lookup) with host information (not including the
+    os.environ).
+    """
     host_platform = spack.platforms.host()
-    host_target = host_platform.default_target()
-    host_os = host_platform.default_operating_system()
+    host_target = host_platform.target("default_target")
+    host_os = host_platform.operating_system("default_os")
     arch_fmt = "platform={0} os={1} target={2}"
     arch_spec = Spec(arch_fmt.format(host_platform, host_os, host_target))
     return {

lib/spack/spack/test/architecture.py

@@ -60,7 +60,8 @@ def test_user_input_combination(config, target_str, os_str):
     """Test for all the valid user input combinations that both the target and
     the operating system match.
     """
-    spec = Spec(f"libelf os={os_str} target={target_str}")
+    spec_str = "libelf os={} target={}".format(os_str, target_str)
+    spec = Spec(spec_str)
     assert spec.architecture.os == str(TEST_PLATFORM.operating_system(os_str))
     assert spec.architecture.target == TEST_PLATFORM.target(target_str)
 
@@ -70,8 +71,8 @@ def test_default_os_and_target(default_mock_concretization):
     after concretization.
     """
     spec = default_mock_concretization("libelf")
-    assert spec.architecture.os == str(TEST_PLATFORM.default_operating_system())
-    assert spec.architecture.target == TEST_PLATFORM.default_target()
+    assert spec.architecture.os == str(TEST_PLATFORM.operating_system("default_os"))
+    assert spec.architecture.target == TEST_PLATFORM.target("default_target")
 
 
 def test_operating_system_conversion_to_dict():

lib/spack/spack/test/ci.py

@@ -1,10 +1,8 @@
 # Copyright Spack Project Developers. See COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-import io
 import os
 import subprocess
-from urllib.error import HTTPError
 
 import pytest
 
@@ -17,7 +15,6 @@
 import spack.paths as spack_paths
 import spack.repo as repo
 import spack.util.git
-from spack.test.conftest import MockHTTPResponse
 
 pytestmark = [pytest.mark.usefixtures("mock_packages")]
 
@@ -165,8 +162,38 @@ def test_import_signing_key(mock_gnupghome):
     ci.import_signing_key(signing_key)
 
 
-def test_download_and_extract_artifacts(tmpdir, monkeypatch):
-    monkeypatch.setenv("GITLAB_PRIVATE_TOKEN", "faketoken")
+class FakeWebResponder:
+    def __init__(self, response_code=200, content_to_read=[]):
+        self._resp_code = response_code
+        self._content = content_to_read
+        self._read = [False for c in content_to_read]
+
+    def open(self, request, data=None, timeout=object()):
+        return self
+
+    def getcode(self):
+        return self._resp_code
+
+    def read(self, length=None):
+        if len(self._content) <= 0:
+            return None
+
+        if not self._read[-1]:
+            return_content = self._content[-1]
+            if length:
+                self._read[-1] = True
+            else:
+                self._read.pop()
+                self._content.pop()
+            return return_content
+
+        self._read.pop()
+        self._content.pop()
+        return None
+
+
+def test_download_and_extract_artifacts(tmpdir, monkeypatch, working_env):
+    os.environ.update({"GITLAB_PRIVATE_TOKEN": "faketoken"})
 
     url = "https://www.nosuchurlexists.itsfake/artifacts.zip"
     working_dir = os.path.join(tmpdir.strpath, "repro")
@@ -174,13 +201,10 @@ def test_download_and_extract_artifacts(tmpdir, monkeypatch):
         spack_paths.test_path, "data", "ci", "gitlab", "artifacts.zip"
     )
 
-    def _urlopen_OK(*args, **kwargs):
-        with open(test_artifacts_path, "rb") as f:
-            return MockHTTPResponse(
-                "200", "OK", {"Content-Type": "application/zip"}, io.BytesIO(f.read())
-            )
+    with open(test_artifacts_path, "rb") as fd:
+        fake_responder = FakeWebResponder(content_to_read=[fd.read()])
 
-    monkeypatch.setattr(ci, "urlopen", _urlopen_OK)
+    monkeypatch.setattr(ci, "build_opener", lambda handler: fake_responder)
 
     ci.download_and_extract_artifacts(url, working_dir)
 
@@ -190,11 +214,7 @@ def _urlopen_OK(*args, **kwargs):
     found_install = fs.find(working_dir, "install.sh")
     assert len(found_install) == 1
 
-    def _urlopen_500(*args, **kwargs):
-        raise HTTPError(url, 500, "Internal Server Error", {}, None)
-
-    monkeypatch.setattr(ci, "urlopen", _urlopen_500)
-
+    fake_responder._resp_code = 400
     with pytest.raises(spack.error.SpackError):
         ci.download_and_extract_artifacts(url, working_dir)
 
@@ -308,14 +328,16 @@ def test_get_spec_filter_list(mutable_mock_env_path, mutable_mock_repo):
     e1.add("hypre")
     e1.concretize()
 
-    # Concretizing the above environment results in the following graphs:
+    """
+    Concretizing the above environment results in the following graphs:
 
-    # mpileaks -> mpich (provides mpi virtual dep of mpileaks)
-    #          -> callpath -> dyninst -> libelf
-    #                                 -> libdwarf -> libelf
-    #                      -> mpich (provides mpi dep of callpath)
+    mpileaks -> mpich (provides mpi virtual dep of mpileaks)
+             -> callpath -> dyninst -> libelf
+                                    -> libdwarf -> libelf
+                         -> mpich (provides mpi dep of callpath)
 
-    # hypre -> openblas-with-lapack (provides lapack and blas virtual deps of hypre)
+    hypre -> openblas-with-lapack (provides lapack and blas virtual deps of hypre)
+    """
 
     touched = ["libdwarf"]
 

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

@@ -329,14 +329,14 @@ def test_ci_generate_pkg_with_deps(ci_generate_test, tmp_path, ci_base_environme
         f"""\
 spack:
   specs:
-    - dependent-install
+    - flatten-deps
   mirrors:
     buildcache-destination: {tmp_path / 'ci-mirror'}
   ci:
     pipeline-gen:
     - submapping:
       - match:
-          - dependent-install
+          - flatten-deps
         build-job:
           tags:
             - donotcare
@@ -355,12 +355,12 @@ def test_ci_generate_pkg_with_deps(ci_generate_test, tmp_path, ci_base_environme
             assert "stage" in ci_obj
             assert ci_obj["stage"] == "stage-0"
             found.append("dependency-install")
-        if "dependent-install" in ci_key:
+        if "flatten-deps" in ci_key:
             assert "stage" in ci_obj
             assert ci_obj["stage"] == "stage-1"
-            found.append("dependent-install")
+            found.append("flatten-deps")
 
-    assert "dependent-install" in found
+    assert "flatten-deps" in found
     assert "dependency-install" in found
 
 
@@ -372,14 +372,14 @@ def test_ci_generate_for_pr_pipeline(ci_generate_test, tmp_path, monkeypatch):
         f"""\
 spack:
   specs:
-    - dependent-install
+    - flatten-deps
   mirrors:
     buildcache-destination: {tmp_path / 'ci-mirror'}
   ci:
     pipeline-gen:
     - submapping:
       - match:
-          - dependent-install
+          - flatten-deps
         build-job:
           tags:
             - donotcare
@@ -899,7 +899,7 @@ def test_ci_generate_override_runner_attrs(
         f"""\
 spack:
   specs:
-    - dependent-install
+    - flatten-deps
     - pkg-a
   mirrors:
     buildcache-destination: {tmp_path / "ci-mirror"}
@@ -908,7 +908,7 @@ def test_ci_generate_override_runner_attrs(
     - match_behavior: {match_behavior}
       submapping:
         - match:
-            - dependent-install
+            - flatten-deps
           build-job:
             tags:
               - specific-one
@@ -1006,8 +1006,8 @@ def test_ci_generate_override_runner_attrs(
             assert the_elt["script"][0] == "main step"
             assert len(the_elt["after_script"]) == 1
             assert the_elt["after_script"][0] == "post step one"
-        if "dependent-install" in ci_key:
-            # The dependent-install match specifies that we keep the two
+        if "flatten-deps" in ci_key:
+            # The flatten-deps match specifies that we keep the two
             # top level variables, but add a third specifc one.  It
             # also adds a custom tag which should be combined with
             # the top-level tag.
@@ -1182,12 +1182,12 @@ def test_ci_generate_read_broken_specs_url(
     spec_a = spack.concretize.concretize_one("pkg-a")
     a_dag_hash = spec_a.dag_hash()
 
-    spec_flattendeps = spack.concretize.concretize_one("dependent-install")
+    spec_flattendeps = spack.concretize.concretize_one("flatten-deps")
     flattendeps_dag_hash = spec_flattendeps.dag_hash()
 
     broken_specs_url = tmp_path.as_uri()
 
-    # Mark 'a' as broken (but not 'dependent-install')
+    # Mark 'a' as broken (but not 'flatten-deps')
     broken_spec_a_url = "{0}/{1}".format(broken_specs_url, a_dag_hash)
     job_stack = "job_stack"
     a_job_url = "a_job_url"
@@ -1201,7 +1201,7 @@ def test_ci_generate_read_broken_specs_url(
             f"""\
 spack:
   specs:
-    - dependent-install
+    - flatten-deps
     - pkg-a
   mirrors:
     buildcache-destination: {(tmp_path / "ci-mirror").as_uri()}
@@ -1211,7 +1211,7 @@ def test_ci_generate_read_broken_specs_url(
     - submapping:
       - match:
           - pkg-a
-          - dependent-install
+          - flatten-deps
           - pkg-b
           - dependency-install
         build-job:
@@ -1234,7 +1234,7 @@ def test_ci_generate_read_broken_specs_url(
             )
             assert expected in output
 
-            not_expected = f"dependent-install/{flattendeps_dag_hash[:7]} (in stack"
+            not_expected = f"flatten-deps/{flattendeps_dag_hash[:7]} (in stack"
             assert not_expected not in output
 
 
@@ -1447,7 +1447,7 @@ def test_gitlab_config_scopes(ci_generate_test, tmp_path):
   include: [{configs_path}]
   view: false
   specs:
-    - dependent-install
+    - flatten-deps
   mirrors:
     buildcache-destination: {tmp_path / "ci-mirror"}
   ci:

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

@@ -51,8 +51,8 @@ def test_create_db_tarball(tmpdir, database):
 def test_report():
     out = debug("report")
     host_platform = spack.platforms.host()
-    host_os = host_platform.default_operating_system()
-    host_target = host_platform.default_target()
+    host_os = host_platform.operating_system("frontend")
+    host_target = host_platform.target("frontend")
     architecture = spack.spec.ArchSpec((str(host_platform), str(host_os), str(host_target)))
 
     assert spack.get_version() in out

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

@@ -24,24 +24,32 @@
 mpi_deps = ["fake"]
 
 
-@pytest.mark.parametrize(
-    "cli_args,expected",
-    [
-        (["mpileaks"], set(["callpath"] + mpis)),
-        (
-            ["--transitive", "mpileaks"],
-            set(["callpath", "dyninst", "libdwarf", "libelf"] + mpis + mpi_deps),
-        ),
-        (["--transitive", "--deptype=link,run", "dtbuild1"], {"dtlink2", "dtrun2"}),
-        (["--transitive", "--deptype=build", "dtbuild1"], {"dtbuild2", "dtlink2"}),
-        (["--transitive", "--deptype=link", "dtbuild1"], {"dtlink2"}),
-    ],
-)
-def test_direct_dependencies(cli_args, expected, mock_runtimes):
-    out = dependencies(*cli_args)
-    result = set(re.split(r"\s+", out.strip()))
-    expected.update(mock_runtimes)
-    assert expected == result
+def test_direct_dependencies(mock_packages):
+    out = dependencies("mpileaks")
+    actual = set(re.split(r"\s+", out.strip()))
+    expected = set(["callpath"] + mpis)
+    assert expected == actual
+
+
+def test_transitive_dependencies(mock_packages):
+    out = dependencies("--transitive", "mpileaks")
+    actual = set(re.split(r"\s+", out.strip()))
+    expected = set(["callpath", "dyninst", "libdwarf", "libelf"] + mpis + mpi_deps)
+    assert expected == actual
+
+
+def test_transitive_dependencies_with_deptypes(mock_packages):
+    out = dependencies("--transitive", "--deptype=link,run", "dtbuild1")
+    deps = set(re.split(r"\s+", out.strip()))
+    assert set(["dtlink2", "dtrun2"]) == deps
+
+    out = dependencies("--transitive", "--deptype=build", "dtbuild1")
+    deps = set(re.split(r"\s+", out.strip()))
+    assert set(["dtbuild2", "dtlink2"]) == deps
+
+    out = dependencies("--transitive", "--deptype=link", "dtbuild1")
+    deps = set(re.split(r"\s+", out.strip()))
+    assert set(["dtlink2"]) == deps
 
 
 @pytest.mark.db

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

@@ -1038,58 +1038,6 @@ def test_init_from_yaml(environment_from_manifest):
     assert not e2.specs_by_hash
 
 
-def test_init_from_yaml_relative_includes(tmp_path):
-    files = [
-        "relative_copied/packages.yaml",
-        "./relative_copied/compilers.yaml",
-        "repos.yaml",
-        "./config.yaml",
-    ]
-
-    manifest = f"""
-spack:
-  specs: []
-  include: {files}
-"""
-
-    e1_path = tmp_path / "e1"
-    e1_manifest = e1_path / "spack.yaml"
-    fs.mkdirp(e1_path)
-    with open(e1_manifest, "w", encoding="utf-8") as f:
-        f.write(manifest)
-
-    for f in files:
-        fs.touchp(e1_path / f)
-
-    e2 = _env_create("test2", init_file=e1_manifest)
-
-    for f in files:
-        assert os.path.exists(os.path.join(e2.path, f))
-
-
-def test_init_from_yaml_relative_includes_outside_env(tmp_path):
-    files = ["../outside_env_not_copied/repos.yaml"]
-
-    manifest = f"""
-spack:
-  specs: []
-  include: {files}
-"""
-
-    # subdir to ensure parent of environment dir is not shared
-    e1_path = tmp_path / "e1_subdir" / "e1"
-    e1_manifest = e1_path / "spack.yaml"
-    fs.mkdirp(e1_path)
-    with open(e1_manifest, "w", encoding="utf-8") as f:
-        f.write(manifest)
-
-    for f in files:
-        fs.touchp(e1_path / f)
-
-    with pytest.raises(spack.config.ConfigFileError, match="Detected 1 missing include"):
-        _ = _env_create("test2", init_file=e1_manifest)
-
-
 def test_env_view_external_prefix(tmp_path, mutable_database, mock_packages):
     fake_prefix = tmp_path / "a-prefix"
     fake_bin = fake_prefix / "bin"
@@ -2666,7 +2614,7 @@ def test_stack_yaml_remove_from_matrix_no_effect(tmpdir):
     - packages:
         - matrix:
             - [mpileaks, callpath]
-            - [target=default_target]
+            - [target=be]
   specs:
     - $packages
 """
@@ -2691,7 +2639,7 @@ def test_stack_yaml_force_remove_from_matrix(tmpdir):
     - packages:
         - matrix:
             - [mpileaks, callpath]
-            - [target=default_target]
+            - [target=be]
   specs:
     - $packages
 """
@@ -2711,7 +2659,7 @@ def test_stack_yaml_force_remove_from_matrix(tmpdir):
 
             assert before_user == after_user
 
-            mpileaks_spec = Spec("mpileaks target=default_target")
+            mpileaks_spec = Spec("mpileaks target=be")
             assert mpileaks_spec in before_conc
             assert mpileaks_spec not in after_conc
 

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

@@ -139,7 +139,7 @@ def test_gc_except_specific_environments(mutable_database, mutable_mock_env_path
 def test_gc_except_nonexisting_dir_env(mutable_database, mutable_mock_env_path, tmpdir):
     output = gc("-ye", tmpdir.strpath, fail_on_error=False)
     assert "No such environment" in output
-    assert gc.returncode == 1
+    gc.returncode == 1
 
 
 @pytest.mark.db

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

@@ -26,9 +26,9 @@ def test_manpath_trailing_colon(
         else ("--sh", "export %s=%s", ";")
     )
 
-    # Test that the commands generated by load add the MANPATH prefix
-    # inspections. Also test that Spack correctly preserves the default/existing
-    # manpath search path via a trailing colon
+    """Test that the commands generated by load add the MANPATH prefix
+    inspections. Also test that Spack correctly preserves the default/existing
+    manpath search path via a trailing colon"""
     install("mpileaks")
 
     sh_out = load(shell, "mpileaks")
@@ -81,9 +81,7 @@ def extract_value(output, variable):
 
         # Finally, do we list them in topo order?
         for i, pkg in enumerate(pkgs):
-            assert {s.name for s in mpileaks_spec[pkg].traverse(direction="parents")}.issubset(
-                pkgs[: i + 1]
-            )
+            set(s.name for s in mpileaks_spec[pkg].traverse(direction="parents")) in set(pkgs[:i])
 
         # Lastly, do we keep track that mpileaks was loaded?
         assert (

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

@@ -304,8 +304,6 @@ def test_run_import_check(tmp_path: pathlib.Path):
     contents = '''
 import spack.cmd
 import spack.config  # do not drop this import because of this comment
-import spack.repo
-import spack.repo_utils
 
 # this comment about spack.error should not be removed
 class Example(spack.build_systems.autotools.AutotoolsPackage):
@@ -316,7 +314,6 @@ def foo(config: "spack.error.SpackError"):
     # the type hint is quoted, so it should not be removed
     spack.util.executable.Executable("example")
     print(spack.__version__)
-    print(spack.repo_utils.__file__)
 '''
     file.write_text(contents)
     root = str(tmp_path)
@@ -332,7 +329,6 @@ def foo(config: "spack.error.SpackError"):
     output = output_buf.getvalue()
 
     assert "issues.py: redundant import: spack.cmd" in output
-    assert "issues.py: redundant import: spack.repo" in output
     assert "issues.py: redundant import: spack.config" not in output  # comment prevents removal
     assert "issues.py: missing import: spack" in output  # used by spack.__version__
     assert "issues.py: missing import: spack.build_systems.autotools" in output

lib/spack/spack/test/concretization/core.py

@@ -148,6 +148,7 @@ def current_host(request, monkeypatch):
     cpu, _, is_preference = request.param.partition("-")
 
     monkeypatch.setattr(spack.platforms.Test, "default", cpu)
+    monkeypatch.setattr(spack.platforms.Test, "front_end", cpu)
     if not is_preference:
         target = archspec.cpu.TARGETS[cpu]
         monkeypatch.setattr(archspec.cpu, "host", lambda: target)
@@ -384,11 +385,10 @@ def test_different_compilers_get_different_flags(
     ):
         """Tests that nodes get the flags of the associated compiler."""
         mutable_config.set("compilers", [clang12_with_flags, gcc11_with_flags])
-        t = archspec.cpu.host().family
         client = spack.concretize.concretize_one(
             Spec(
-                f"cmake-client %gcc@11.1.0 platform=test os=redhat6 target={t}"
-                f" ^cmake %clang@12.2.0 platform=test os=redhat6 target={t}"
+                "cmake-client %gcc@11.1.0 platform=test os=fe target=fe"
+                " ^cmake %clang@12.2.0 platform=test os=fe target=fe"
             )
         )
         cmake = client["cmake"]
@@ -413,8 +413,7 @@ def test_spec_flags_maintain_order(self, mutable_config, gcc11_with_flags):
     def test_compiler_flags_differ_identical_compilers(self, mutable_config, clang12_with_flags):
         mutable_config.set("compilers", [clang12_with_flags])
         # Correct arch to use test compiler that has flags
-        t = archspec.cpu.host().family
-        spec = Spec(f"pkg-a %clang@12.2.0 platform=test os=redhat6 target={t}")
+        spec = Spec("pkg-a %clang@12.2.0 platform=test os=fe target=fe")
 
         # Get the compiler that matches the spec (
         compiler = spack.compilers.compiler_for_spec("clang@=12.2.0", spec.architecture)
@@ -1243,7 +1242,7 @@ def test_transitive_conditional_virtual_dependency(self, mutable_config):
     def test_conditional_provides_or_depends_on(self):
         # Check that we can concretize correctly a spec that can either
         # provide a virtual or depend on it based on the value of a variant
-        s = spack.concretize.concretize_one("v1-consumer ^conditional-provider +disable-v1")
+        s = spack.concretize.concretize_one("conditional-provider +disable-v1")
         assert "v1-provider" in s
         assert s["v1"].name == "v1-provider"
         assert s["v2"].name == "conditional-provider"
@@ -2112,15 +2111,14 @@ def test_installed_specs_disregard_conflicts(self, mutable_database, monkeypatch
     def test_require_targets_are_allowed(self, mutable_database):
         """Test that users can set target constraints under the require attribute."""
         # Configuration to be added to packages.yaml
-        required_target = archspec.cpu.TARGETS[spack.platforms.test.Test.default].family
-        external_conf = {"all": {"require": f"target={required_target}"}}
+        external_conf = {"all": {"require": "target=%s" % spack.platforms.test.Test.front_end}}
         spack.config.set("packages", external_conf)
 
         with spack.config.override("concretizer:reuse", False):
             spec = spack.concretize.concretize_one("mpich")
 
         for s in spec.traverse():
-            assert s.satisfies(f"target={required_target}")
+            assert s.satisfies("target=%s" % spack.platforms.test.Test.front_end)
 
     def test_external_python_extensions_have_dependency(self):
         """Test that python extensions have access to a python dependency

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

@@ -1,6 +1,17 @@
 # Copyright Spack Project Developers. See COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
+import pathlib
+
+import pytest
+
+import spack.concretize
+import spack.config
+import spack.environment as ev
+import spack.paths
+import spack.repo
+import spack.spec
+import spack.util.spack_yaml as syaml
 
 """
 These tests include the following package DAGs:
@@ -31,18 +42,6 @@
 y
 """
 
-import pathlib
-
-import pytest
-
-import spack.concretize
-import spack.config
-import spack.environment as ev
-import spack.paths
-import spack.repo
-import spack.spec
-import spack.util.spack_yaml as syaml
-
 
 @pytest.fixture
 def test_repo(mutable_config, monkeypatch, mock_stage):

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

@@ -259,7 +259,7 @@ def test_develop(self):
     def test_external_mpi(self):
         # make sure this doesn't give us an external first.
         spec = spack.concretize.concretize_one("mpi")
-        assert not spec.external and spec.package.provides("mpi")
+        assert not spec["mpi"].external
 
         # load config
         conf = syaml.load_config(
@@ -293,7 +293,7 @@ def mock_module(cmd, module):
         monkeypatch.setattr(spack.util.module_cmd, "module", mock_module)
 
         spec = spack.concretize.concretize_one("mpi")
-        assert not spec.external and spec.package.provides("mpi")
+        assert not spec["mpi"].external
 
         # load config
         conf = syaml.load_config(

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

@@ -1,6 +1,7 @@
 # Copyright Spack Project Developers. See COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
+import os
 import pathlib
 
 import pytest
@@ -181,7 +182,7 @@ def test_requirement_adds_version_satisfies(
 
     # Sanity check: early version of T does not include U
     s0 = spack.concretize.concretize_one("t@2.0")
-    assert "u" not in s0
+    assert not ("u" in s0)
 
     conf_str = """\
 packages:
@@ -199,11 +200,11 @@ def test_requirement_adds_version_satisfies(
 
 @pytest.mark.parametrize("require_checksum", (True, False))
 def test_requirement_adds_git_hash_version(
-    require_checksum, concretize_scope, test_repo, mock_git_version_info, monkeypatch
+    require_checksum, concretize_scope, test_repo, mock_git_version_info, monkeypatch, working_env
 ):
     # A full commit sha is a checksummed version, so this test should pass in both cases
     if require_checksum:
-        monkeypatch.setenv("SPACK_CONCRETIZER_REQUIRE_CHECKSUM", "yes")
+        os.environ["SPACK_CONCRETIZER_REQUIRE_CHECKSUM"] = "yes"
 
     repo_path, filename, commits = mock_git_version_info
     monkeypatch.setattr(

lib/spack/spack/test/config.py

@@ -408,7 +408,7 @@ def test_substitute_config_variables(mock_low_high_config, monkeypatch):
         os.path.join("foo", "$platform", "bar")
     ) == os.path.abspath(os.path.join("foo", "test", "bar"))
 
-    host_target = spack.platforms.host().default_target()
+    host_target = spack.platforms.host().target("default_target")
     host_target_family = str(host_target.family)
     assert spack_path.canonicalize_path(
         os.path.join("foo", "$target_family", "bar")

lib/spack/spack/test/conftest.py

@@ -621,7 +621,7 @@ def linux_os():
     platform = spack.platforms.host()
     name, version = "debian", "6"
     if platform.name == "linux":
-        current_os = platform.default_operating_system()
+        current_os = platform.operating_system("default_os")
         name, version = current_os.name, current_os.version
     LinuxOS = collections.namedtuple("LinuxOS", ["name", "version"])
     return LinuxOS(name=name, version=version)
@@ -680,6 +680,7 @@ def load_json():
 def mock_targets(mock_uarch_configuration, monkeypatch):
     """Use this fixture to enable mock uarch targets for testing."""
     targets_json, targets = mock_uarch_configuration
+
     monkeypatch.setattr(archspec.cpu.schema, "TARGETS_JSON", targets_json)
     monkeypatch.setattr(archspec.cpu.microarchitecture, "TARGETS", targets)
 
@@ -2171,8 +2172,3 @@ def getcode(self):
 
     def info(self):
         return self.headers
-
-
-@pytest.fixture()
-def mock_runtimes(config, mock_packages):
-    return mock_packages.packages_with_tags("runtime")

lib/spack/spack/test/cray_manifest.py

@@ -13,8 +13,6 @@
 
 import pytest
 
-import archspec.cpu
-
 import spack
 import spack.cmd
 import spack.cmd.external
@@ -100,8 +98,11 @@ def spec_json(self):
 
 @pytest.fixture
 def _common_arch(test_platform):
-    generic = archspec.cpu.TARGETS[test_platform.default].family
-    return JsonArchEntry(platform=test_platform.name, os="redhat6", target=generic.name)
+    return JsonArchEntry(
+        platform=test_platform.name,
+        os=test_platform.front_os,
+        target=test_platform.target("fe").name,
+    )
 
 
 @pytest.fixture

lib/spack/spack/test/directives.py

@@ -206,7 +206,7 @@ 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 spack.repo.PATH.get_pkg_class(spec.fullname).redistribute_source(spec) == distribute_src
+    assert spec.package_class.redistribute_source(spec) == distribute_src
     concretized_spec = spack.concretize.concretize_one(spec)
     assert concretized_spec.package.redistribute_binary == distribute_bin
 

lib/spack/spack/test/install.py

@@ -198,6 +198,17 @@ def test_installed_dependency_request_conflicts(install_mockery, mock_fetch, mut
         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 = spack.concretize.concretize_one("flatten-deps")
+    pkg = spec.package
+    PackageInstaller([pkg], explicit=True).install()
+
+    # Ensure dependency directory exists after the installation.
+    dependency_dir = os.path.join(pkg.prefix, "dependency-install")
+    assert os.path.isdir(dependency_dir)
+
+
 def test_install_times(install_mockery, mock_fetch, mutable_mock_repo):
     """Test install times added."""
     spec = spack.concretize.concretize_one("dev-build-test-install-phases")
@@ -217,6 +228,26 @@ def test_install_times(install_mockery, mock_fetch, mutable_mock_repo):
     assert all(isinstance(x["seconds"], float) for x in times["phases"])
 
 
+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 = spack.concretize.concretize_one("dependent-install")
+    pkg = spec.package
+    PackageInstaller([pkg], explicit=True).install()
+
+    # Demonstrate that the directory does not appear under the spec
+    # prior to the flatten operation.
+    dependency_name = "dependency-install"
+    assert dependency_name not in os.listdir(pkg.prefix)
+
+    # Flatten the dependencies and ensure the dependency directory is there.
+    spack.package_base.flatten_dependencies(spec, pkg.prefix)
+
+    dependency_dir = os.path.join(pkg.prefix, dependency_name)
+    assert os.path.isdir(dependency_dir)
+
+
 @pytest.fixture()
 def install_upstream(tmpdir_factory, gen_mock_layout, install_mockery):
     """Provides a function that installs a specified set of specs to an
@@ -458,7 +489,7 @@ def test_log_install_without_build_files(install_mockery):
     spec = spack.concretize.concretize_one("trivial-install-test-package")
 
     # Attempt installing log without the build log file
-    with pytest.raises(OSError, match="No such file or directory"):
+    with pytest.raises(IOError, match="No such file or directory"):
         spack.installer.log(spec.package)
 
 

lib/spack/spack/test/installer.py

@@ -470,7 +470,7 @@ def _repoerr(repo, name):
 
     # The call to install_tree will raise the exception since not mocking
     # creation of dependency package files within *install* directories.
-    with pytest.raises(OSError, match=path if sys.platform != "win32" else ""):
+    with pytest.raises(IOError, match=path if sys.platform != "win32" else ""):
         inst.dump_packages(spec, path)
 
     # Now try the error path, which requires the mock directory structure

lib/spack/spack/test/llnl/util/filesystem.py

@@ -82,7 +82,7 @@ def test_non_existing_src(self, stage):
         """Test using a non-existing source."""
 
         with fs.working_dir(str(stage)):
-            with pytest.raises(OSError, match="No such file or directory"):
+            with pytest.raises(IOError, match="No such file or directory"):
                 fs.copy("source/none", "dest")
 
     def test_multiple_src_file_dest(self, stage):
@@ -139,7 +139,7 @@ def test_non_existing_src(self, stage):
         """Test using a non-existing source."""
 
         with fs.working_dir(str(stage)):
-            with pytest.raises(OSError, match="No such file or directory"):
+            with pytest.raises(IOError, match="No such file or directory"):
                 fs.install("source/none", "dest")
 
     def test_multiple_src_file_dest(self, stage):
@@ -220,7 +220,7 @@ def test_non_existing_src(self, stage):
         """Test using a non-existing source."""
 
         with fs.working_dir(str(stage)):
-            with pytest.raises(OSError, match="No such file or directory"):
+            with pytest.raises(IOError, match="No such file or directory"):
                 fs.copy_tree("source/none", "dest")
 
     def test_parent_dir(self, stage):
@@ -301,7 +301,7 @@ def test_non_existing_src(self, stage):
         """Test using a non-existing source."""
 
         with fs.working_dir(str(stage)):
-            with pytest.raises(OSError, match="No such file or directory"):
+            with pytest.raises(IOError, match="No such file or directory"):
                 fs.install_tree("source/none", "dest")
 
     def test_parent_dir(self, stage):

lib/spack/spack/test/llnl/util/lock.py

@@ -93,26 +93,28 @@
     pass
 
 
-#: This is a list of filesystem locations to test locks in.  Paths are
-#: expanded so that %u is replaced with the current username. '~' is also
-#: legal and will be expanded to the user's home directory.
-#:
-#: Tests are skipped for directories that don't exist, so you'll need to
-#: update this with the locations of NFS, Lustre, and other mounts on your
-#: system.
+"""This is a list of filesystem locations to test locks in.  Paths are
+expanded so that %u is replaced with the current username. '~' is also
+legal and will be expanded to the user's home directory.
+
+Tests are skipped for directories that don't exist, so you'll need to
+update this with the locations of NFS, Lustre, and other mounts on your
+system.
+"""
 locations = [
     tempfile.gettempdir(),
     os.path.join("/nfs/tmp2/", getpass.getuser()),
     os.path.join("/p/lscratch*/", getpass.getuser()),
 ]
 
-#: This is the longest a failed multiproc test will take.
-#: Barriers will time out and raise an exception after this interval.
-#: In MPI mode, barriers don't time out (they hang).  See mpi_multiproc_test.
+"""This is the longest a failed multiproc test will take.
+Barriers will time out and raise an exception after this interval.
+In MPI mode, barriers don't time out (they hang).  See mpi_multiproc_test.
+"""
 barrier_timeout = 5
 
-#: This is the lock timeout for expected failures.
-#: This may need to be higher for some filesystems.
+"""This is the lock timeout for expected failures.
+This may need to be higher for some filesystems."""
 lock_fail_timeout = 0.1
 
 
@@ -284,8 +286,9 @@ def wait(self):
     comm.Barrier()  # barrier after each MPI test.
 
 
-#: ``multiproc_test()`` should be called by tests below.
-#: ``multiproc_test()`` will work for either MPI runs or for local runs.
+"""``multiproc_test()`` should be called by tests below.
+``multiproc_test()`` will work for either MPI runs or for local runs.
+"""
 multiproc_test = mpi_multiproc_test if mpi else local_multiproc_test
 
 
@@ -1336,7 +1339,7 @@ def test_poll_lock_exception(tmpdir, monkeypatch, err_num, err_msg):
     """Test poll lock exception handling."""
 
     def _lockf(fd, cmd, len, start, whence):
-        raise OSError(err_num, err_msg)
+        raise IOError(err_num, err_msg)
 
     with tmpdir.as_cwd():
         lockfile = "lockfile"
@@ -1348,7 +1351,7 @@ def _lockf(fd, cmd, len, start, whence):
         if err_num in [errno.EAGAIN, errno.EACCES]:
             assert not lock._poll_lock(fcntl.LOCK_EX)
         else:
-            with pytest.raises(OSError, match=err_msg):
+            with pytest.raises(IOError, match=err_msg):
                 lock._poll_lock(fcntl.LOCK_EX)
 
         monkeypatch.undo()

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

@@ -238,7 +238,10 @@ def test_exclude(self, modulefile_content, module_configuration, host_architectu
 
         assert len([x for x in content if "module load " in x]) == 1
 
-        with pytest.raises(FileNotFoundError):
+        # Catch "Exception" to avoid using FileNotFoundError on Python 3
+        # and IOError on Python 2 or common bases like EnvironmentError
+        # which are not officially documented
+        with pytest.raises(Exception):
             modulefile_content(f"callpath target={host_architecture_str}")
 
         content = modulefile_content(f"zmpi target={host_architecture_str}")

lib/spack/spack/test/package_class.py

@@ -1,6 +1,7 @@
 # Copyright Spack Project Developers. See COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
 """Test class methods on Package objects.
 
 This doesn't include methods on package *instances* (like do_patch(),
@@ -15,7 +16,6 @@
 
 import llnl.util.filesystem as fs
 
-import spack.binary_distribution
 import spack.compilers
 import spack.concretize
 import spack.deptypes as dt
@@ -23,11 +23,15 @@
 import spack.install_test
 import spack.package
 import spack.package_base
+import spack.repo
 import spack.spec
-import spack.store
 from spack.build_systems.generic import Package
 from spack.error import InstallError
-from spack.solver.input_analysis import NoStaticAnalysis, StaticAnalysis
+
+
+@pytest.fixture(scope="module")
+def mpi_names(mock_repo_path):
+    return [spec.name for spec in mock_repo_path.providers_for("mpi")]
 
 
 @pytest.fixture()
@@ -49,94 +53,78 @@ def mpileaks_possible_deps(mock_packages, mpi_names):
     return possible
 
 
-@pytest.fixture(params=[NoStaticAnalysis, StaticAnalysis])
-def mock_inspector(config, mock_packages, request):
-    inspector_cls = request.param
-    if inspector_cls is NoStaticAnalysis:
-        return inspector_cls(configuration=config, repo=mock_packages)
-    return inspector_cls(
-        configuration=config,
-        repo=mock_packages,
-        store=spack.store.STORE,
-        binary_index=spack.binary_distribution.BINARY_INDEX,
+def test_possible_dependencies(mock_packages, mpileaks_possible_deps):
+    pkg_cls = spack.repo.PATH.get_pkg_class("mpileaks")
+    expanded_possible_deps = pkg_cls.possible_dependencies(expand_virtuals=True)
+    assert mpileaks_possible_deps == expanded_possible_deps
+    assert {
+        "callpath": {"dyninst", "mpi"},
+        "dyninst": {"libdwarf", "libelf"},
+        "libdwarf": {"libelf"},
+        "libelf": set(),
+        "mpi": set(),
+        "mpileaks": {"callpath", "mpi"},
+    } == pkg_cls.possible_dependencies(expand_virtuals=False)
+
+
+def test_possible_direct_dependencies(mock_packages, mpileaks_possible_deps):
+    pkg_cls = spack.repo.PATH.get_pkg_class("mpileaks")
+    deps = pkg_cls.possible_dependencies(transitive=False, expand_virtuals=False)
+    assert {"callpath": set(), "mpi": set(), "mpileaks": {"callpath", "mpi"}} == deps
+
+
+def test_possible_dependencies_virtual(mock_packages, mpi_names):
+    expected = dict(
+        (name, set(dep for dep in spack.repo.PATH.get_pkg_class(name).dependencies_by_name()))
+        for name in mpi_names
+    )
+
+    # only one mock MPI has a dependency
+    expected["fake"] = set()
+
+    assert expected == spack.package_base.possible_dependencies("mpi", transitive=False)
+
+
+def test_possible_dependencies_missing(mock_packages):
+    pkg_cls = spack.repo.PATH.get_pkg_class("missing-dependency")
+    missing = {}
+    pkg_cls.possible_dependencies(transitive=True, missing=missing)
+    assert {"this-is-a-missing-dependency"} == missing["missing-dependency"]
+
+
+def test_possible_dependencies_with_deptypes(mock_packages):
+    dtbuild1 = spack.repo.PATH.get_pkg_class("dtbuild1")
+
+    assert {
+        "dtbuild1": {"dtrun2", "dtlink2"},
+        "dtlink2": set(),
+        "dtrun2": set(),
+    } == dtbuild1.possible_dependencies(depflag=dt.LINK | dt.RUN)
+
+    assert {
+        "dtbuild1": {"dtbuild2", "dtlink2"},
+        "dtbuild2": set(),
+        "dtlink2": set(),
+    } == dtbuild1.possible_dependencies(depflag=dt.BUILD)
+
+    assert {"dtbuild1": {"dtlink2"}, "dtlink2": set()} == dtbuild1.possible_dependencies(
+        depflag=dt.LINK
     )
 
 
-@pytest.fixture
-def mpi_names(mock_inspector):
-    return [spec.name for spec in mock_inspector.providers_for("mpi")]
-
-
-@pytest.mark.parametrize(
-    "pkg_name,fn_kwargs,expected",
-    [
-        (
-            "mpileaks",
-            {"expand_virtuals": True, "allowed_deps": dt.ALL},
-            {
-                "fake",
-                "mpileaks",
-                "multi-provider-mpi",
-                "callpath",
-                "dyninst",
-                "mpich2",
-                "libdwarf",
-                "zmpi",
-                "low-priority-provider",
-                "intel-parallel-studio",
-                "mpich",
-                "libelf",
-            },
-        ),
-        (
-            "mpileaks",
-            {"expand_virtuals": False, "allowed_deps": dt.ALL},
-            {"callpath", "dyninst", "libdwarf", "libelf", "mpileaks"},
-        ),
-        (
-            "mpileaks",
-            {"expand_virtuals": False, "allowed_deps": dt.ALL, "transitive": False},
-            {"callpath", "mpileaks"},
-        ),
-        ("dtbuild1", {"allowed_deps": dt.LINK | dt.RUN}, {"dtbuild1", "dtrun2", "dtlink2"}),
-        ("dtbuild1", {"allowed_deps": dt.BUILD}, {"dtbuild1", "dtbuild2", "dtlink2"}),
-        ("dtbuild1", {"allowed_deps": dt.LINK}, {"dtbuild1", "dtlink2"}),
-    ],
-)
-def test_possible_dependencies(pkg_name, fn_kwargs, expected, mock_runtimes, mock_inspector):
-    """Tests possible nodes of mpileaks, under different scenarios."""
-    expected.update(mock_runtimes)
-    result, *_ = mock_inspector.possible_dependencies(pkg_name, **fn_kwargs)
-    assert expected == result
-
-
-def test_possible_dependencies_virtual(mock_inspector, mock_packages, mock_runtimes, mpi_names):
-    expected = set(mpi_names)
-    for name in mpi_names:
-        expected.update(dep for dep in mock_packages.get_pkg_class(name).dependencies_by_name())
-    expected.update(mock_runtimes)
-
-    real_pkgs, *_ = mock_inspector.possible_dependencies(
-        "mpi", transitive=False, allowed_deps=dt.ALL
-    )
-    assert expected == real_pkgs
-
-
-def test_possible_dependencies_missing(mock_inspector):
-    result, *_ = mock_inspector.possible_dependencies("missing-dependency", allowed_deps=dt.ALL)
-    assert "this-is-a-missing-dependency" not in result
-
-
-def test_possible_dependencies_with_multiple_classes(
-    mock_inspector, mock_packages, mpileaks_possible_deps
-):
+def test_possible_dependencies_with_multiple_classes(mock_packages, mpileaks_possible_deps):
     pkgs = ["dt-diamond", "mpileaks"]
-    expected = set(mpileaks_possible_deps)
-    expected.update({"dt-diamond", "dt-diamond-left", "dt-diamond-right", "dt-diamond-bottom"})
-    expected.update(mock_packages.packages_with_tags("runtime"))
+    expected = mpileaks_possible_deps.copy()
+    expected.update(
+        {
+            "dt-diamond": set(["dt-diamond-left", "dt-diamond-right"]),
+            "dt-diamond-left": set(["dt-diamond-bottom"]),
+            "dt-diamond-right": set(["dt-diamond-bottom"]),
+            "dt-diamond-bottom": set(),
+        }
+    )
 
-    real_pkgs, *_ = mock_inspector.possible_dependencies(*pkgs, allowed_deps=dt.ALL)
-    assert set(expected) == real_pkgs
+    assert expected == spack.package_base.possible_dependencies(*pkgs)
 
 
 def setup_install_test(source_paths, test_root):

lib/spack/spack/test/reporters.py

@@ -132,8 +132,7 @@ def test_reporters_extract_skipped(state):
     parts = spack.reporters.extract.extract_test_parts("fake", outputs)
 
     assert len(parts) == 1
-
-    assert parts[0]["completed"] == spack.reporters.extract.completed["skipped"]
+    parts[0]["completed"] == expected
 
 
 def test_reporters_skip_new():

lib/spack/spack/test/sbang.py

@@ -198,7 +198,7 @@ def script_dir(sbang_line):
     ],
 )
 def test_shebang_interpreter_regex(shebang, interpreter):
-    assert sbang.get_interpreter(shebang) == interpreter
+    sbang.get_interpreter(shebang) == interpreter
 
 
 def test_shebang_handling(script_dir, sbang_line):

lib/spack/spack/test/spec_dag.py

@@ -319,6 +319,7 @@ def test_dependents_and_dependencies_are_correct(self):
             ("mpich@1.0", "mpileaks ^mpich@2.0"),
             ("mpich%gcc", "mpileaks ^mpich%intel"),
             ("mpich%gcc@4.6", "mpileaks ^mpich%gcc@4.5"),
+            ("mpich platform=test target=be", "mpileaks ^mpich platform=test target=fe"),
         ],
     )
     def test_unsatisfiable_cases(self, set_dependency, constraint_str, spec_str):
@@ -428,29 +429,31 @@ def test_copy_through_spec_build_interface(self):
         c2 = s["mpileaks"]["mpileaks"].copy()
         assert c0 == c1 == c2 == s
 
-    # Here is the graph with deptypes labeled (assume all packages have a 'dt'
-    # prefix). Arrows are marked with the deptypes ('b' for 'build', 'l' for
-    # 'link', 'r' for 'run').
+    """
+    Here is the graph with deptypes labeled (assume all packages have a 'dt'
+    prefix). Arrows are marked with the deptypes ('b' for 'build', 'l' for
+    'link', 'r' for 'run').
 
-    #     use -bl-> top
+        use -bl-> top
 
-    #     top -b->  build1
-    #     top -bl-> link1
-    #     top -r->  run1
+        top -b->  build1
+        top -bl-> link1
+        top -r->  run1
 
-    #     build1 -b->  build2
-    #     build1 -bl-> link2
-    #     build1 -r->  run2
+        build1 -b->  build2
+        build1 -bl-> link2
+        build1 -r->  run2
 
-    #     link1 -bl-> link3
+        link1 -bl-> link3
 
-    #     run1 -bl-> link5
-    #     run1 -r->  run3
+        run1 -bl-> link5
+        run1 -r->  run3
 
-    #     link3 -b->  build2
-    #     link3 -bl-> link4
+        link3 -b->  build2
+        link3 -bl-> link4
 
-    #     run3 -b-> build3
+        run3 -b-> build3
+    """
 
     @pytest.mark.parametrize(
         "spec_str,deptypes,expected",

lib/spack/spack/test/spec_semantics.py

@@ -460,6 +460,7 @@ def test_concrete_specs_which_satisfies_abstract(self, lhs, rhs, default_mock_co
             ("foo platform=linux", "platform=test os=redhat6 target=x86"),
             ("foo os=redhat6", "platform=test os=debian6 target=x86_64"),
             ("foo target=x86_64", "platform=test os=redhat6 target=x86"),
+            ("foo arch=test-frontend-frontend", "platform=test os=frontend target=backend"),
             ("foo%intel", "%gcc"),
             ("foo%intel", "%gcc"),
             ("foo%gcc@4.3", "%gcc@4.4:4.6"),
@@ -486,6 +487,7 @@ def test_concrete_specs_which_satisfies_abstract(self, lhs, rhs, default_mock_co
             ("libelf+debug", "libelf~debug"),
             ("libelf+debug~foo", "libelf+debug+foo"),
             ("libelf debug=True", "libelf debug=False"),
+            ("libelf platform=test target=be os=be", "libelf target=fe os=fe"),
             ("namespace=builtin.mock", "namespace=builtin"),
         ],
     )
@@ -1989,26 +1991,3 @@ def test_equality_discriminate_on_propagation(lhs, rhs):
 
 def test_comparison_multivalued_variants():
     assert Spec("x=a") < Spec("x=a,b") < Spec("x==a,b") < Spec("x==a,b,c")
-
-
-def test_comparison_after_breaking_hash_change():
-    # We simulate a breaking change in DAG hash computation in Spack. We have two specs that are
-    # entirely equal modulo DAG hash. When deserializing these specs, we don't want them to compare
-    # as equal, because DAG hash is used throughout in Spack to distinguish between specs
-    # (e.g. database, build caches, install dir).
-    s = Spec("example@=1.0")
-    s._mark_concrete(True)
-
-    # compute the dag hash and a change to it
-    dag_hash = s.dag_hash()
-    new_dag_hash = f"{'b' if dag_hash[0] == 'a' else 'a'}{dag_hash[1:]}"
-
-    before_breakage = s.to_dict()
-    after_breakage = s.to_dict()
-    after_breakage["spec"]["nodes"][0]["hash"] = new_dag_hash
-    assert before_breakage != after_breakage
-
-    x = Spec.from_dict(before_breakage)
-    y = Spec.from_dict(after_breakage)
-    assert x != y
-    assert len({x, y}) == 2

lib/spack/spack/test/spec_syntax.py

@@ -306,7 +306,7 @@ def _specfile_for(spec_str, filename):
         (
             r"os=fe",  # Various translations associated with the architecture
             [Token(SpecTokens.KEY_VALUE_PAIR, value="os=fe")],
-            "arch=test-debian6-None",
+            "arch=test-redhat6-None",
         ),
         (
             r"os=default_os",
@@ -999,14 +999,14 @@ def test_disambiguate_hash_by_spec(spec1, spec2, constraint, mock_packages, monk
         ("x arch=linux-rhel7-ppc64le arch=linux-rhel7-x86_64", "two architectures"),
         ("y ^x arch=linux-rhel7-x86_64 arch=linux-rhel7-x86_64", "two architectures"),
         ("y ^x arch=linux-rhel7-x86_64 arch=linux-rhel7-ppc64le", "two architectures"),
-        ("x os=redhat6 os=debian6", "'os'"),
-        ("x os=debian6 os=redhat6", "'os'"),
-        ("x target=core2 target=x86_64", "'target'"),
-        ("x target=x86_64 target=core2", "'target'"),
+        ("x os=fe os=fe", "'os'"),
+        ("x os=fe os=be", "'os'"),
+        ("x target=fe target=fe", "'target'"),
+        ("x target=fe target=be", "'target'"),
         ("x platform=test platform=test", "'platform'"),
         # TODO: these two seem wrong: need to change how arch is initialized (should fail on os)
-        ("x os=debian6 platform=test target=default_target os=redhat6", "two architectures"),
-        ("x target=default_target platform=test os=redhat6 os=debian6", "'platform'"),
+        ("x os=fe platform=test target=fe os=fe", "'platform'"),
+        ("x target=be platform=test os=be os=fe", "'platform'"),
         # Dependencies
         ("^[@foo] zlib", "edge attributes"),
         ("x ^[deptypes=link]foo ^[deptypes=run]foo", "conflicting dependency types"),

lib/spack/spack/test/stage.py

@@ -125,7 +125,7 @@ def check_expand_archive(stage, stage_name, expected_file_list):
 
         assert os.path.isfile(fn)
         with open(fn, encoding="utf-8") as _file:
-            assert _file.read() == contents
+            _file.read() == contents
 
 
 def check_fetch(stage, stage_name):

lib/spack/spack/test/util/compression.py

@@ -20,7 +20,12 @@
 
 datadir = os.path.join(spack_root, "lib", "spack", "spack", "test", "data", "compression")
 
-ext_archive = {ext: f"Foo.{ext}" for ext in llnl.url.ALLOWED_ARCHIVE_TYPES if "TAR" not in ext}
+ext_archive = {}
+[
+    ext_archive.update({ext: ".".join(["Foo", ext])})
+    for ext in llnl.url.ALLOWED_ARCHIVE_TYPES
+    if "TAR" not in ext
+]
 # Spack does not use Python native handling for tarballs or zip
 # Don't test tarballs or zip in native test
 native_archive_list = [

lib/spack/spack/test/util/editor.py

@@ -204,13 +204,13 @@ def test_no_editor():
     def assert_exec(exe, args):
         assert False
 
-    with pytest.raises(OSError, match=r"No text editor found.*"):
+    with pytest.raises(EnvironmentError, match=r"No text editor found.*"):
         ed.editor("/path/to/file", exec_fn=assert_exec)
 
     def assert_exec(exe, args):
         return False
 
-    with pytest.raises(OSError, match=r"No text editor found.*"):
+    with pytest.raises(EnvironmentError, match=r"No text editor found.*"):
         ed.editor("/path/to/file", exec_fn=assert_exec)
 
 
@@ -220,5 +220,5 @@ def test_exec_fn_executable(editor_var, good_exe, bad_exe):
     assert ed.editor(exec_fn=ed.executable)
 
     os.environ[editor_var] = bad_exe
-    with pytest.raises(OSError, match=r"No text editor found.*"):
+    with pytest.raises(EnvironmentError, match=r"No text editor found.*"):
         ed.editor(exec_fn=ed.executable)

lib/spack/spack/test/util/elf.py

@@ -201,15 +201,3 @@ def test_drop_redundant_rpath(tmpdir, binary_with_rpaths):
     new_rpaths = elf.get_rpaths(binary)
     assert set(existing_dirs).issubset(new_rpaths)
     assert set(non_existing_dirs).isdisjoint(new_rpaths)
-
-
-def test_elf_invalid_e_shnum(tmp_path):
-    # from llvm/test/Object/Inputs/invalid-e_shnum.elf
-    path = tmp_path / "invalid-e_shnum.elf"
-    with open(path, "wb") as file:
-        file.write(
-            b"\x7fELF\x02\x010000000000\x03\x00>\x0000000000000000000000"
-            b"\x00\x00\x00\x00\x00\x00\x00\x000000000000@\x000000"
-        )
-    with open(path, "rb") as file, pytest.raises(elf.ElfParsingError):
-        elf.parse_elf(file)