changed exception to be ValueError when cache directory is a file, in…

…stead of a FileExistsError

pydra/utils/hash.py

@@ -60,7 +60,12 @@ def location_converter(path: ty.Union[Path, str, None]) -> Path:
     if path is None:
         path = PersistentCache.location_default()
     path = Path(path)
-    path.mkdir(parents=True, exist_ok=True)
+    try:
+        path.mkdir(parents=True, exist_ok=True)
+    except FileExistsError:
+        raise ValueError(
+            f"provided path to persistent cache {path} is a file not a directory"
+        ) from None
     return path
 
 

pydra/utils/tests/test_hash.py

@@ -384,5 +384,5 @@ def test_persistent_hash_cache_not_dir(text_file):
     """
     Test that an error is raised if the provided cache path is not a directory
     """
-    with pytest.raises(FileExistsError):
+    with pytest.raises(ValueError, match="not a directory"):
         PersistentCache(text_file.fspath)