kivy/kivy — pull request #658 by waldobronchart (2012-08-30 21:53:10+00:00)
Title: Fixed bug with adding a Camera widget in .kv file

The resolution property is not initialized before _on_index() is called.
So the app crashes because [-1, -1] is not a supported resolution.

...
Camera:
resolution: (640, 480)
index: 0