> It's supposed to remove non-ascii characters.
>
> I think this is a leftover from the py2->py3 conversion. It looks like an overenthusiastic regexp replacement in the 2to3 tool. See bb5775ef where it came from. I'll go change it to jut str(err).
Right. Beware that there are other similar failing conversions in the same commit on lines in loader/lib/parser.py that should be addressed as well
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Célestin Matte