Failure to start activities - Cannot create a consistent method resolution order (MRO)

[greenfeld]

Very rarely a Sugar activity fails to start (usually for the first time), logging an exception in the activity log. The last time I saw this was with Typing Turtle in 13.1.0 os8; I may have seen this once with Read or Browse as well.

The following is seen in the activity log when this happens. Launching the activity again usually succeeds.

Traceback (most recent call last):
  File "/usr/bin/sugar-activity", line 160, in <module>
    main()
  File "/usr/bin/sugar-activity", line 118, in main
    module = __import__(module_name)
  File "/home/olpc/Activities/TypingTurtle.activity/typingturtle.py", line 32, in <module>
    from gi.repository import Gtk
  File "/usr/lib/python2.7/site-packages/gi/importer.py", line 76, in load_module
    dynamic_module._load()
  File "/usr/lib/python2.7/site-packages/gi/module.py", line 244, in _load
    overrides_modules = __import__('gi.overrides', fromlist=[self._namespace])
  File "/usr/lib/python2.7/site-packages/gi/overrides/Gtk.py", line 993, in <module>
    class TreeModelSort(Gtk.TreeModelSort):
  File "/usr/lib/python2.7/site-packages/gi/module.py", line 193, in __getattr__
    wrapper = metaclass(name, bases, dict_)
  File "/usr/lib/python2.7/site-packages/gi/types.py", line 243, in mro
    return mro(cls)
  File "/usr/lib/python2.7/site-packages/gi/types.py", line 257, in mro
    bases_of_subclasses += list(map(mro, C.__bases__)) + [list(C.__bases__)]
  File "/usr/lib/python2.7/site-packages/gi/types.py", line 257, in mro
    bases_of_subclasses += list(map(mro, C.__bases__)) + [list(C.__bases__)]
  File "/usr/lib/python2.7/site-packages/gi/types.py", line 269, in mro
    raise TypeError('Cannot create a consistent method resolution '
TypeError: Cannot create a consistent method resolution order (MRO)
Exited with status 1, pid 1207 data (None, <open file '<fdopen>', mode 'w' at 0x137aac8>, 'a4bbec364ef73d5791bb8c8f7c1258244baad095')

[dsd]

Also seen in #3488, #3503 and #4116.

Can we identify which XO laptop models are affected? Just in case that has something to do with it. #4116 states XO-4, the other cases do not explicitly state which laptop model it was reproduced on.

[godiard]

I reproduced this a few times in xo-4.

[bert]

Seen in os9 with Browse right after updating from os8.

[dsd]

For all future reports please state which laptop model and software version this was seen on.

13.1.0 build 12 for XO-4 includes a general fix (​http://dev.laptop.org/ticket/12164) which was seen to make some other Python code run badly. So it would be interesting to see if this is spotted again on 13.1.0 build 12 or newer on XO-4.

[dsd]

We think this was fixed for XO-4 as described above.

The same issue may exist on XO-1.75, but we only have one documented case of that happening. Please reopen if this is seen again.

[dnarvaez]

Milestone 0.98 deleted