Could `tito build --srpm --test` bump setup.py version?

[praiskup]

There's a convenient logic to bump Python version for tito tag, though it would be very nice if we could dump the "pre-release" version into the Python version string.

Background story: I'm thinking about self-identifying copr-rpmbuild script in its logs; if some pre-release copr-rpmbuild is being run, it would be nice to dump into logs the full version, e.g. 0.69-1.git.4.6f7e09b instead of just 0.69.

[FrostyX]

We have the undocumented "templates" feature, I am using it here:

https://github.com/FrostyX/tracer/blob/master/rel-eng/templates/version.rb
https://github.com/FrostyX/tracer/blob/master/rel-eng/tito.props

but IIRC it is used when tagging, not when building. Maybe we can improve it.

[praiskup]

The problem is that setup.py is added to the git archive tarball. And we don't want to modify it on the fly - or maybe, do we? But that would be precedent, even with the "spec file modifications" for build --test we only modify the spec file copy that is not archived in the underlying tarball.

[praiskup]

This may now conflict with the #460, at least it does in python-copr-common (see the last commit).