Spack tests no longer clutter var/spack/stage

- Tests use a session-scoped mock stage directory so as not to interfere
  with the real install.

- Every test is forced to clean up after itself with an additional check.
  We now automatically assert that no new files have been added to
  `spack.stage_path` during each test.

  - This means that tests that fail installs now need to clean up their
    stages, but in all other cases the check is useful.

1 files changed, 28 insertions, 26 deletions

diff --git a/lib/spack/spack/test/install.py b/lib/spack/spack/test/install.py
index 454adbac5e..cf08642dfa 100644
--- a/lib/spack/spack/test/install.py
+++ b/lib/spack/spack/test/install.py
@@ -69,46 +69,49 @@ class MockStage(object):
         self.test_destroyed = False
 
     def __enter__(self):
+        self.create()
         return self
 
-    def __exit__(self, *exc):
-        return True
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if exc_type is None:
+            self.destroy()
 
     def destroy(self):
         self.test_destroyed = True
         self.wrapped_stage.destroy()
 
+    def create(self):
+        self.wrapped_stage.create()
+
     def __getattr__(self, attr):
         return getattr(self.wrapped_stage, attr)
 
 
 def test_partial_install_delete_prefix_and_stage(install_mockery, mock_fetch):
-    spec = Spec('canfail')
-    spec.concretize()
+    spec = Spec('canfail').concretized()
     pkg = spack.repo.get(spec)
     remove_prefix = spack.package.Package.remove_prefix
     instance_rm_prefix = pkg.remove_prefix
 
     try:
+        pkg.succeed = False
         spack.package.Package.remove_prefix = mock_remove_prefix
         with pytest.raises(MockInstallError):
             pkg.do_install()
         assert os.path.isdir(pkg.prefix)
         rm_prefix_checker = RemovePrefixChecker(instance_rm_prefix)
         spack.package.Package.remove_prefix = rm_prefix_checker.remove_prefix
-        setattr(pkg, 'succeed', True)
+
+        pkg.succeed = True
         pkg.stage = MockStage(pkg.stage)
+
         pkg.do_install(restage=True)
         assert rm_prefix_checker.removed
         assert pkg.stage.test_destroyed
         assert pkg.installed
+
     finally:
         spack.package.Package.remove_prefix = remove_prefix
-        pkg._stage = None
-        try:
-            delattr(pkg, 'succeed')
-        except AttributeError:
-            pass
 
 
 def test_dont_add_patches_to_installed_package(install_mockery, mock_fetch):
@@ -141,53 +144,50 @@ def test_installed_dependency_request_conflicts(
         dependent.concretize()
 
 
+@pytest.mark.disable_clean_stage_check
 def test_partial_install_keep_prefix(install_mockery, mock_fetch):
-    spec = Spec('canfail')
-    spec.concretize()
+    spec = Spec('canfail').concretized()
     pkg = spack.repo.get(spec)
+
     # Normally the stage should start unset, but other tests set it
     pkg._stage = None
     remove_prefix = spack.package.Package.remove_prefix
     try:
         # If remove_prefix is called at any point in this test, that is an
         # error
+        pkg.succeed = False  # make the build fail
         spack.package.Package.remove_prefix = mock_remove_prefix
         with pytest.raises(spack.build_environment.ChildError):
             pkg.do_install(keep_prefix=True)
         assert os.path.exists(pkg.prefix)
-        setattr(pkg, 'succeed', True)
+
+        pkg.succeed = True   # make the build succeed
         pkg.stage = MockStage(pkg.stage)
         pkg.do_install(keep_prefix=True)
         assert pkg.installed
         assert not pkg.stage.test_destroyed
+
     finally:
         spack.package.Package.remove_prefix = remove_prefix
-        pkg._stage = None
-        try:
-            delattr(pkg, 'succeed')
-        except AttributeError:
-            pass
 
 
 def test_second_install_no_overwrite_first(install_mockery, mock_fetch):
-    spec = Spec('canfail')
-    spec.concretize()
+    spec = Spec('canfail').concretized()
     pkg = spack.repo.get(spec)
     remove_prefix = spack.package.Package.remove_prefix
     try:
         spack.package.Package.remove_prefix = mock_remove_prefix
-        setattr(pkg, 'succeed', True)
+
+        pkg.succeed = True
         pkg.do_install()
         assert pkg.installed
+
         # If Package.install is called after this point, it will fail
-        delattr(pkg, 'succeed')
+        pkg.succeed = False
         pkg.do_install()
+
     finally:
         spack.package.Package.remove_prefix = remove_prefix
-        try:
-            delattr(pkg, 'succeed')
-        except AttributeError:
-            pass
 
 
 def test_store(install_mockery, mock_fetch):
@@ -196,9 +196,11 @@ def test_store(install_mockery, mock_fetch):
     pkg.do_install()
 
 
+@pytest.mark.disable_clean_stage_check
 def test_failing_build(install_mockery, mock_fetch):
     spec = Spec('failing-build').concretized()
     pkg = spec.package
+
     with pytest.raises(spack.build_environment.ChildError):
         pkg.do_install()