related issue: https://bugs.python.org/issue20853

similarly to this, if args cmd is used in pdb in the TestClass __init__ method, `self` will be displayed, which means the TestClass.__str__ or __repr__ will run, lacking any required state set in the __init__ after current line; - causing an exception and pdb quitting.

I wonder if one fix can be applied to both issues. I will think about it. I'll also think if this issue should be reopened.