Revert "Testing: fix unintended interactions between tests (#16003)" (#16420)

This was breaking tests on develop.

lib/spack/spack/cmd/compiler.py

@@ -159,19 +159,7 @@ def compiler_list(args):
     tty.msg("Available compilers")
     index = index_by(spack.compilers.all_compilers(scope=args.scope),
                      lambda c: (c.spec.name, c.operating_system, c.target))
-
-    # For a container, take each element which does not evaluate to false and
-    # convert it to a string. For elements which evaluate to False (e.g. None)
-    # convert them to '' (in which case it still evaluates to False but is a
-    # string type). Tuples produced by this are guaranteed to be comparable in
-    # Python 3
-    convert_str = (
-        lambda tuple_container:
-        tuple(str(x) if x else '' for x in tuple_container))
-
-    index_str_keys = list(
-        (convert_str(x), y) for x, y in index.items())
-    ordered_sections = sorted(index_str_keys, key=lambda item: item[0])
+    ordered_sections = sorted(index.items(), key=lambda item: item[0])
     for i, (key, compilers) in enumerate(ordered_sections):
         if i >= 1:
             print()

lib/spack/spack/test/concretize.py

@@ -12,6 +12,7 @@
 
 from spack.concretize import find_spec, NoValidVersionError
 from spack.error import SpecError
+from spack.package_prefs import PackagePrefs
 from spack.spec import Spec, CompilerSpec, ConflictsInSpecError
 from spack.version import ver
 from spack.util.mock_package import MockPackageMultiRepo
@@ -102,6 +103,8 @@ def current_host(request, monkeypatch):
         monkeypatch.setattr(spack.platforms.test.Test, 'default', cpu)
         yield target
     else:
+        # There's a cache that needs to be cleared for unit tests
+        PackagePrefs._packages_config_cache = None
         with spack.config.override('packages:all', {'target': [cpu]}):
             yield target
 
@@ -109,10 +112,7 @@ def current_host(request, monkeypatch):
     spack.architecture.get_platform.cache.clear()
 
 
-# This must use the mutable_config fixture because the test
-# adjusting_default_target_based_on_compiler uses the current_host fixture,
-# which changes the config.
-@pytest.mark.usefixtures('mutable_config', 'mock_packages')
+@pytest.mark.usefixtures('config', 'mock_packages')
 class TestConcretize(object):
     def test_concretize(self, spec):
         check_concretize(spec)

lib/spack/spack/test/concretize_preferences.py

@@ -100,7 +100,7 @@ def test_preferred_compilers(self):
         # Try the last available compiler
         compiler = str(compiler_list[-1])
         update_packages('mpileaks', 'compiler', [compiler])
-        spec = concretize('mpileaks os=redhat6 target=x86')
+        spec = concretize('mpileaks')
         assert spec.compiler == spack.spec.CompilerSpec(compiler)
 
     def test_preferred_target(self, mutable_mock_repo):

lib/spack/spack/test/conftest.py

@@ -423,13 +423,13 @@ def config(mock_configuration):
 
 
 @pytest.fixture(scope='function')
-def mutable_config(tmpdir_factory, configuration_dir):
+def mutable_config(tmpdir_factory, configuration_dir, monkeypatch):
     """Like config, but tests can modify the configuration."""
     mutable_dir = tmpdir_factory.mktemp('mutable_config').join('tmp')
     configuration_dir.copy(mutable_dir)
 
     cfg = spack.config.Configuration(
-        *[spack.config.ConfigScope(name, str(mutable_dir.join(name)))
+        *[spack.config.ConfigScope(name, str(mutable_dir))
           for name in ['site', 'system', 'user']])
 
     with use_configuration(cfg):

lib/spack/spack/test/data/config/packages.yaml

@@ -1,7 +1,4 @@
 packages:
-  all:
-    providers:
-      mpi: [openmpi, mpich]
   externaltool:
     buildable: False
     paths: