warn if module is found but fails to import in PIL.features

Author: nulano

src/PIL/features.py

@@ -33,7 +33,10 @@ def check_module(feature):
     try:
         __import__(module)
         return True
-    except ImportError:
+    except ModuleNotFoundError:
+        return False
+    except ImportError as ex:
+        warnings.warn(str(ex))
         return False
 
 
@@ -145,7 +148,10 @@ def check_feature(feature):
     try:
         imported_module = __import__(module, fromlist=["PIL"])
         return getattr(imported_module, flag)
-    except ImportError:
+    except ModuleNotFoundError:
+        return None
+    except ImportError as ex:
+        warnings.warn(str(ex))
         return None