Ah, I see.  A link to that issue would have been helpful :).

To summarize for anyone like me who didn't follow that issue: __index__ means the object can be losslessly converted to an int (is a true int), while __int__ may be an approximate conversion.  Thus it makes sense for an object to have an __int__ but not __index__, but vice-versa does not make sense.

Is someone updating the docs to reflect this, or should that be spun off as a separate issue as well?