AppConfig.create swallows informative exceptions during import time
|Reported by:||bendavis78||Owned by:||aaugustin|
|Severity:||Normal||Keywords:||AppConfig app-loading ImportError|
|Has patch:||yes||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
If you have an INSTALLED_APPS entry that doesn't use an AppConfig, and that module has more than one level, eg "myproject.myapp", AppConfig.create will swallow any exceptions that occur during the import of that module, losing valuable traceback information. The create method makes some incorrect assumptions about the entry. Mainly it assumes that if the entry has more than one part and the import fails, that it must be an AppConfig class (which is incorrect).
I've submitted a PR with a fix for this. Basically the new algorithm is as follows:
- Split the entry into mod_path and ending. If it's a single-level module, ending is empty.
- Attempt to import mod_path as module, allowing exceptions to propagate (no try/catch)
- Check if ending is an attribute of module.
- If the attribute doesn't exist OR the attribute exists and is a module, import the full entry as module (again, allowing exceptions to propagate)
- If the imported module does NOT a default_app_config attr, return with a default AppConfig instance.
- Otherwise, import the module path from default_app_config entry as module (again, allowing exceptions to propagate), and assume the ending is a class name.
- If ending was an attribute of module in step 3, we can assume it's an AppConfig class.
- At this point we have a legitimate module and an object which should be a class, and can continue on to validate the AppConfig class.
Change History (6)
comment:1 Changed 22 months ago by bendavis78
- Has patch set
- Needs documentation unset
- Needs tests unset
- Patch needs improvement unset
comment:2 Changed 22 months ago by aaugustin
- Keywords app-loading added; app loading removed
- Owner changed from nobody to aaugustin
- Severity changed from Release blocker to Normal
- Status changed from new to assigned
- Triage Stage changed from Unreviewed to Accepted
comment:5 Changed 20 months ago by Aymeric Augustin <aymeric.augustin@…>
- Resolution set to fixed
- Status changed from assigned to closed