kivy/kivy — pull request #1623 by mike-perdide (2013-11-19 16:53:59+00:00)
Title: When no Text provider is found, provide message instead of Error.

When core_select_lib doesn't find a proper provider, it prints some log
messages, but does not return any object nor raises an Exception.
Therefore, we get an AttributeError when trying to do
Label.register(...).

The error is: AttributeError: 'NoneType' object has no attribute
'register'

Fixes bug #1622