types: remove singleton union in globals (#47282)

lib/spack/spack/caches.py

@@ -5,7 +5,6 @@
 
 """Caches used by Spack to store data"""
 import os
-from typing import Union
 
 import llnl.util.lang
 from llnl.util.filesystem import mkdirp
@@ -32,12 +31,8 @@ def _misc_cache():
     return spack.util.file_cache.FileCache(path)
 
 
-FileCacheType = Union[spack.util.file_cache.FileCache, llnl.util.lang.Singleton]
-
 #: Spack's cache for small data
-MISC_CACHE: Union[spack.util.file_cache.FileCache, llnl.util.lang.Singleton] = (
+MISC_CACHE: spack.util.file_cache.FileCache = llnl.util.lang.Singleton(_misc_cache)  # type: ignore
-    llnl.util.lang.Singleton(_misc_cache)
-)
 
 
 def fetch_cache_location():
@@ -74,6 +69,4 @@ def store(self, fetcher, relative_dest):
 
 
 #: Spack's local cache for downloaded source archives
-FETCH_CACHE: Union[spack.fetch_strategy.FsCache, llnl.util.lang.Singleton] = (
+FETCH_CACHE: spack.fetch_strategy.FsCache = llnl.util.lang.Singleton(_fetch_cache)  # type: ignore
-    llnl.util.lang.Singleton(_fetch_cache)
-)

lib/spack/spack/config.py

@@ -714,7 +714,7 @@ def print_section(self, section: str, blame: bool = False, *, scope=None) -> Non
 @contextlib.contextmanager
 def override(
     path_or_scope: Union[ConfigScope, str], value: Optional[Any] = None
-) -> Generator[Union[lang.Singleton, Configuration], None, None]:
+) -> Generator[Configuration, None, None]:
     """Simple way to override config settings within a context.
 
     Arguments:
@@ -756,9 +756,7 @@ def override(
 COMMAND_LINE_SCOPES: List[str] = []
 
 
-def _add_platform_scope(
+def _add_platform_scope(cfg: Configuration, name: str, path: str, writable: bool = True) -> None:
-    cfg: Union[Configuration, lang.Singleton], name: str, path: str, writable: bool = True
-) -> None:
     """Add a platform-specific subdirectory for the current platform."""
     platform = spack.platforms.host().name
     scope = DirectoryConfigScope(
@@ -792,9 +790,7 @@ def config_paths_from_entry_points() -> List[Tuple[str, str]]:
     return config_paths
 
 
-def _add_command_line_scopes(
+def _add_command_line_scopes(cfg: Configuration, command_line_scopes: List[str]) -> None:
-    cfg: Union[Configuration, lang.Singleton], command_line_scopes: List[str]
-) -> None:
     """Add additional scopes from the --config-scope argument, either envs or dirs."""
     import spack.environment.environment as env  # circular import
 
@@ -875,7 +871,7 @@ def create() -> Configuration:
 
 
 #: This is the singleton configuration instance for Spack.
-CONFIG: Union[Configuration, lang.Singleton] = lang.Singleton(create)
+CONFIG: Configuration = lang.Singleton(create)  # type: ignore
 
 
 def add_from_file(filename: str, scope: Optional[str] = None) -> None:

lib/spack/spack/repo.py

@@ -41,6 +41,7 @@
 import spack.provider_index
 import spack.spec
 import spack.tag
+import spack.util.file_cache
 import spack.util.git
 import spack.util.naming as nm
 import spack.util.path
@@ -589,7 +590,7 @@ def __init__(
         self,
         package_checker: FastPackageChecker,
         namespace: str,
-        cache: "spack.caches.FileCacheType",
+        cache: spack.util.file_cache.FileCache,
     ):
         self.checker = package_checker
         self.packages_path = self.checker.packages_path
@@ -682,7 +683,7 @@ class RepoPath:
     def __init__(
         self,
         *repos: Union[str, "Repo"],
-        cache: Optional["spack.caches.FileCacheType"],
+        cache: Optional[spack.util.file_cache.FileCache],
         overrides: Optional[Dict[str, Any]] = None,
     ) -> None:
         self.repos: List[Repo] = []
@@ -964,7 +965,7 @@ def __init__(
         self,
         root: str,
         *,
-        cache: "spack.caches.FileCacheType",
+        cache: spack.util.file_cache.FileCache,
         overrides: Optional[Dict[str, Any]] = None,
     ) -> None:
         """Instantiate a package repository from a filesystem path.
@@ -1439,9 +1440,7 @@ def _path(configuration=None):
     return create(configuration=configuration)
 
 
-def create(
+def create(configuration: spack.config.Configuration) -> RepoPath:
-    configuration: Union["spack.config.Configuration", llnl.util.lang.Singleton]
-) -> RepoPath:
     """Create a RepoPath from a configuration object.
 
     Args:
@@ -1464,7 +1463,7 @@ def create(
 
 
 #: Singleton repo path instance
-PATH: Union[RepoPath, llnl.util.lang.Singleton] = llnl.util.lang.Singleton(_path)
+PATH: RepoPath = llnl.util.lang.Singleton(_path)  # type: ignore
 
 # Add the finder to sys.meta_path
 REPOS_FINDER = ReposFinder()

lib/spack/spack/store.py

@@ -39,9 +39,6 @@
 DEFAULT_INSTALL_TREE_ROOT = os.path.join(spack.paths.opt_path, "spack")
 
 
-ConfigurationType = Union["spack.config.Configuration", "llnl.util.lang.Singleton"]
-
-
 def parse_install_tree(config_dict):
     """Parse config settings and return values relevant to the store object.
 
@@ -207,7 +204,7 @@ def __reduce__(self):
         )
 
 
-def create(configuration: ConfigurationType) -> Store:
+def create(configuration: spack.config.Configuration) -> Store:
     """Create a store from the configuration passed as input.
 
     Args:
@@ -240,7 +237,7 @@ def _create_global() -> Store:
 
 
 #: Singleton store instance
-STORE: Union[Store, llnl.util.lang.Singleton] = llnl.util.lang.Singleton(_create_global)
+STORE: Store = llnl.util.lang.Singleton(_create_global)  # type: ignore
 
 
 def reinitialize():