manage.py validate [app] should display line numbers for syntax errors

[Paul Collier]

When running validate for an app whose models.py file or any file it includes contains a error (most commonly syntax or function argument errors), the listing does not display the offending line/line number/file. This can make deciphering the source of the error difficult--or simply inconvenient, as the info can be obtained by attempting to import the offending model.

[Malcolm Tredinnick]

This can't hurt and looks useful. Moving to "accepted" so that somebody can go to town and write a patch.

[egmanoj@…]

Patch for displaying details such as file name, line number etc. for import errors that occur during 'validate'.

[egmanoj@…]

Added patch.
Please note that non import ("custom") validation errors are still not handled.
For e.g. CharField requires maxlength property to be non-zero. In such cases the error messages will not contain file name, line number etc.

[mcroydon]

django/db/models/loading.py has been refactored and this patch no longer applies.

[Adam Vandenberg]

This doesn't look needed anymore; the refactoring to use an cache no longer does a try/catch around the dynamic imports, so any import-generated exceptions are dumped to the console already.

[Adrian Holovaty]

Couldn't reproduce the problem...Looks like it's been fixed, per the comments above.