Signals are picky about how senders are imported

[Joeboy]

This works as expected:

from myproject.myapp import models as myapp_app
dispatcher.connect( myfunction, signal=signals.post_syncdb, sender=myapp_app)

This fails silently and mysteriously:

from myapp import models as myapp_app
dispatcher.connect( myfunction, signal=signals.post_syncdb, sender=myapp_app)

Thus decoupling is broken, and it takes the uninitiated user (ie. me) ages to work out what the problem is.

[Vinay Sajip <vinay_sajip@…>]

@Joe: Where did you put the above code?

[Joeboy]

Vinay: in myproject/myapp/management.py

[Malcolm Tredinnick]

This is a dupe of #3951 and the discussion over there explains the solution we'll implement.