AttributeError: 'NoneType' object has no attribute 'groups' if tag has the wrong syntax

[plijnzaad]

( I realized that this should be in the setuptools_scm repo so I copied it there, see #471 . Sorry)

I happened to have a git tag of the wrong syntax, namely 2.0.0-alpha.5-PMC, leading to the above error. It was very difficult to track down for a lowly end-user of a package (atropos) that uses it, and which I forked in order to fix a few things. I did not know that tags were needed, let alone be of a very specific shape (and 2.0.0-alpha.5-PMC is not that extreme, right?) .

I have appended the stdout and stderr before git tag --delete 2.0.0-alpha.5-PMC (std*-bad.txt) and after deleting the offending tag (std*-good.txt) (done with export SETUPTOOLS_SCM_DEBUG=verbose)

stdout-bad.txt
stderr-bad.txt

stdout-good.txt
stderr-good.txt

I tried various older versions of setuptools-scm (back to 2.0.0 I recall correctly), all had the same or similar problem. I see several reports of people having similar trouble so it appears to be a general problem and one that occurs more often. I would love if this were more robust, i.e. I'd much rather have a version string 'unknown' or somesuch than a package that refuses to install ...

Cheers,
P

[jaraco]

Dupe of #471 (originally filed with pypa/setuptools)