(bug) phen.py code_errors mask cannot be None

acmc/phen.py

@@ -735,7 +735,7 @@ def _write_code_errors(code_errors: list, code_errors_path: Path):
                 "SOURCE": err.codes_file,
                 "CAUSE": err.message,
             }
-            for err in code_errors
+            for err in code_errors if err.mask is not None
         ]
     )