Middleware Loader swallows useful stacktraces

[davedash]

This try/except block:

​https://github.com/django/django/blob/master/django/core/handlers/base.py#L44

Swallows stacktraces that can help us track down problems. Simply outputting the error raised doesn't really explain what's going on... in our case it was an ImportError caused by a circular import, we had to comment out the try/except to expose it[1].

Not sure what a good way is to fix this, but I thought I'd at the very least mention it.

[1]: ​https://bugzilla.mozilla.org/show_bug.cgi?id=722497

[Claude Paroz]

Maybe just letting the ImportError uncatched? What is the value added by the encapsulation in a ImproperlyConfigured exception?

[Berker Peksag]

The try/except block described in the ticket description is at ​https://github.com/django/django/blob/stable/1.4.x/django/core/handlers/base.py#L42-45

As of Django 1.6+, ImportErrors are not wrapped by ImproperlyConfigured anymore:

• ​https://github.com/django/django/blob/stable/1.6.x/django/core/handlers/base.py#L45
• ​https://github.com/django/django/blob/master/django/core/handlers/base.py#L49