tox >= 3.2.0 breaks module import

[ThomasWaldmann]

After working ok for a long time, suddenly our build on travis-ci (linux) started to fail, having troubles importing the "main" module borg.archiver.

I had the suspicion that it might be due to a tox change / regression, so i downgraded tox and it worked again.

See there for details / links to travis:

borgbackup/borg#4094

[gaborbernat]

Can you investigate and find the actual problem?

[ThomasWaldmann]

The problem is that the import is not working.

I tried to reproduce it locally, but failed to (works ok). Don't feel like debugging this on travis.

[obestwalter]

Hi @ThomasWaldmann I saw you "fixed" it, by freezing the tox version. Did you try again with a recent version of tox? If that problem still occurs it might be worth having a closer look.

[ThomasWaldmann]

@obestwalter I am doing some experiments right now, see issue link above.

[obestwalter]

Still broken then ... https://travis-ci.org/borgbackup/borg/jobs/479214516

What changed between 3.2 and 3.3 was mainly adding pep 517 support, so my hunch is that it has to do with that, but I have no time to look further atm.

Travis CI - Test and Deploy Your Code with Confidence

[ThomasWaldmann]

IIRC, it was the change to 3.2.0 (not: 3.3.0) that broke it.

[obestwalter]

oh <= :). that looks much less suspicious even ...

3.1.0...3.2.0

[ThomasWaldmann]

3.1.3...3.2.0 3.1.3 works, 3.2.0 not, so this is the suspicious diff.

not sure how the dependencies/requirements of tox changed, whether we need to search there also.

[obestwalter]

the changed paths around the thread safe changes can't possibly be it, so then only these changes remain:

3.1.3...3.2.0#diff-a7d930bb82917e733a5436ee035e5842L193

and the deps change to depend on a newer setuptools.

3.1.3...3.2.0#diff-2eeaed663bd0d25b7e608891384b7298L64

I can remember dimly that we tried to change from pip to python -m pip during the sprint in 2016 and had weird effects in one package, so it really might have to do with that.

[rpkilby]

I can remember dimly that we tried to change from pip to python -m pip during the sprint in 2016 and had weird effects in one package, so it really might have to do with that.

I commented on additional pip vs python -m pip weirdness here. I don't know if it's related/helpful, but your comment jogged my memory.

Where I debugged the issue was in encode/django-rest-framework#6139. My solution was to remove the .egg-info, as this interacted with the pip vs python -m pip issue, preventing wheel installation.

tox now invokes pip as a python module instead of through its entry
point. "python -m" adds the current directory to the PYTHONPATH, picking
up the .egg-info/ metadata directory, tricking pip into thinking that
the package is already installed (and thus not installing the wheel).
Deleting the metadata directory fixes this.

[jugmac00]

The OP has moved away from Travis and the affected branch is out of maintenance.

[ThomasWaldmann]

Right, borg 1.0-maint branch won't see updates. Also, we do not currently see this tox issue.