bugfix: ensure all bootstrap context managers are exception-safe

When context managers are used to save and restore values, we need to remember
to use try/finally around the yield in case an exception is thrown.  Otherwise,
the cleanup will be skipped.

lib/spack/spack/architecture.py

@@ -593,17 +593,20 @@ def use_platform(new_platform):
     assert isinstance(new_platform, Platform), msg.format(new_platform)
 
     original_platform_fn, original_all_platforms_fn = platform, all_platforms
-    platform = _PickleableCallable(new_platform)
-    all_platforms = _PickleableCallable([type(new_platform)])
 
-    # Clear configuration and compiler caches
-    spack.config.config.clear_caches()
-    spack.compilers._cache_config_files = []
+    try:
+        platform = _PickleableCallable(new_platform)
+        all_platforms = _PickleableCallable([type(new_platform)])
 
-    yield new_platform
+        # Clear configuration and compiler caches
+        spack.config.config.clear_caches()
+        spack.compilers._cache_config_files = []
 
-    platform, all_platforms = original_platform_fn, original_all_platforms_fn
+        yield new_platform
 
-    # Clear configuration and compiler caches
-    spack.config.config.clear_caches()
-    spack.compilers._cache_config_files = []
+    finally:
+        platform, all_platforms = original_platform_fn, original_all_platforms_fn
+
+        # Clear configuration and compiler caches
+        spack.config.config.clear_caches()
+        spack.compilers._cache_config_files = []

lib/spack/spack/config.py

@@ -1238,11 +1238,12 @@ def use_configuration(*scopes_or_paths):
 
     saved_config, config = config, configuration
 
-    yield configuration
-
-    # Restore previous config files
-    spack.compilers._cache_config_file = saved_compiler_cache
-    config = saved_config
+    try:
+        yield configuration
+    finally:
+        # Restore previous config files
+        spack.compilers._cache_config_file = saved_compiler_cache
+        config = saved_config
 
 
 @llnl.util.lang.memoized

lib/spack/spack/repo.py

@@ -1299,19 +1299,24 @@ def use_repositories(*paths_and_repos):
     """
     global path
 
+    remove_from_meta = None
+
     # Construct a temporary RepoPath object from
     temporary_repositories = RepoPath(*paths_and_repos)
 
     # Swap the current repository out
     saved = path
-    remove_from_meta = set_path(temporary_repositories)
 
-    yield temporary_repositories
+    try:
+        remove_from_meta = set_path(temporary_repositories)
 
-    # Restore _path and sys.meta_path
-    if remove_from_meta:
-        sys.meta_path.remove(temporary_repositories)
-    path = saved
+        yield temporary_repositories
+
+    finally:
+        # Restore _path and sys.meta_path
+        if remove_from_meta:
+            sys.meta_path.remove(temporary_repositories)
+        path = saved
 
 
 class RepoError(spack.error.SpackError):

lib/spack/spack/store.py

@@ -301,9 +301,10 @@ def use_store(store_or_path):
     db, layout = store.db, store.layout
     root, unpadded_root = store.root, store.unpadded_root
 
-    yield temporary_store
-
-    # Restore the original store
-    store = original_store
-    db, layout = original_store.db, original_store.layout
-    root, unpadded_root = original_store.root, original_store.unpadded_root
+    try:
+        yield temporary_store
+    finally:
+        # Restore the original store
+        store = original_store
+        db, layout = original_store.db, original_store.layout
+        root, unpadded_root = original_store.root, original_store.unpadded_root