Try to detect whether the clr module is partially initialised

filmor · filmor · commit 588ef6cff68a · 2021-11-29T14:26:58.000+01:00
This should fix issue pythonnet#1582. While the respective behaviour (setting the member value `_initializing`) is not documented, it has been that way since at least 3.4. As we control `clr`, it can also not happen, that the value is accidentally set.
diff --git a/src/runtime/importhook.cs b/src/runtime/importhook.cs
@@ -44,6 +44,8 @@ def find_spec(klass, fullname, paths=None, target=None):
         if 'clr' not in sys.modules:
             return None
         clr = sys.modules['clr']
+        if getattr(clr, '_initializing', False):
+            return None
 
         clr._add_pending_namespaces()
 
