py3: add alternate output on Python 3
This is basically the same deal as D5806. Python 3's exception
printing output is different.
We had to tweak the regular expression to match appropriately,
hence the added line of output.
Differential Revision: https://phab.mercurial-scm.org/D5807
public attribute not declared in interfaces: badpeer.badattribute
public attribute not declared in interfaces: badpeer.badmethod