Merge pull request #89 from DavidCEllis/fix-immutable-cache

Fix immutable cache

Author: DavidCEllis

src/ducktools/pythonfinder/linux/__init__.py

@@ -80,12 +80,15 @@ def get_path_pythons(
         if not os.path.exists(fld):
             continue
 
-        for install in get_folder_pythons(fld, finder=finder):
-            for path, manager in known_paths.items():
-                if os.path.commonpath((path, install.executable)) == path:
-                    install.managed_by = manager
-                    break
+        # Do the search like this to get subfolders
+        for path, manager in known_paths.items():
+            if os.path.commonpath((path, fld)) == path:
+                managed_by = manager
+                break
+        else:
+            managed_by = None
 
+        for install in get_folder_pythons(fld, finder=finder, managed_by=managed_by):
             name = os.path.basename(install.executable)
             if name in exe_names:
                 install.shadowed = True

src/ducktools/pythonfinder/shared.py

@@ -291,16 +291,21 @@ def get_install_details(
         exe_path = os.path.abspath(exe_path)
         mtime = os.stat(exe_path).st_mtime
 
+        # If the mtime of the file has been set to 0
+        # it is not possible to reliably cache install details
+        cacheable_install = (mtime != 0)
+
         install = None
         if cached_details := self.raw_cache.get(exe_path):
-            if cached_details["mtime"] == mtime:
+            if cacheable_install and cached_details["mtime"] == mtime:
                 install = PythonInstall.from_json(**cached_details["install"])
             else:
                 self.raw_cache.pop(exe_path)
+                self._dirty_cache = True
 
         if install is None:
             install = self.query_install(exe_path, managed_by, metadata)
-            if install:
+            if install and cacheable_install:
                 self.raw_cache[exe_path] = {
                     "mtime": mtime,
                     "install": as_dict(install)