When running the example of wmfreleng/tox for labs/tools/crosswatch (introduced by https://gerrit.wikimedia.org/r/#/c/387728/ )
GLOB sdist-make: /src/setup.py /src$ /usr/bin/python /src/setup.py sdist --formats=zip --dist-dir /src/.tox/dist >/src/.tox/log/tox-0.log WARNING:could not copy distfile to /nonexistent/.tox/distshare
In tox the default is:
distshare=path # (DEPRECATED) defaults to {homedir}/.tox/distshare
But when tox detects Jenkins (via JENKINS_URL) it defaults to {toxworkdir}/distshare
The tox-docker jobs need to pass JENKINS_URL to the container.