Ignore error with non-zero exit status

[Random832]

Thomas 'PointedEars' Lahn writes:
> Chris Angelico wrote:
CA>>>> Proof that percent formatting isn't planned for deprecation, much less
CA>>>> removal.
TL>>> Then it would have failed to accomplish that.
CA>>>> There is strong support for it in certain quarters of python-dev. […]
TL>>> There *was*.  The referred thread is from 2012-02.  It is 2015-12.
CA>> Then show some evidence that python-dev has changed in viewpoint.
TL> And why would I do that?  I have claimed no such thing.

Yes, you have.  Your claim that evidence from 2012 is no longer
relevant is an implicit claim of precisely that.