Fix dist build

[rpkilby]

There is some incompatibility with tox/pytest/virtualenv that causes the 'dist' build to fail. By using the builtin venvs, the issue is bypassed.

I'm also too lazy to figure out why exactly this is happening.

[carltongibson]

Thanks @rpkilby!

(Build still failing though... 😐)

I didn't have time to dig into this. It was fine. What changed?

[rpkilby]

virtualenv/venv was not the cause, that was just correlated to how I was calling tox. The actual issue appears to be a change in tox 3. bisected to tox-dev/tox#935

[rpkilby]

Note that the first call to tox raises an exception, while the second call succeeds. e.g., what I saw when changing from virtualenv to venv.

[carltongibson]

The actual issue appears to be a change in tox 3.

So is the temporary fix to pin the tox version?

[rpkilby]

More info in tox-dev/tox#935 (comment) and pypa/pip#4621 (comment).

Basically, this should be fixable by mucking with pkg_resources. That said, the better fix is to move runtests.py out of the same directory as rest_framework. This would be a slightly larger change, since this would rework how we test coverage/distributions.

[carltongibson]

Right, good digging! 👏

• We'll need to run any reorganisation past @tomchristie. PING 🙂(General thought is that the tools shouldn't really dictate/break a setup that's been working for years... — but things change, so maybe.)
• What's the quickest duct-tape-for-today whilst we work it out? (dist build is useful — I'm a convert to that so it'd be good to have it working in the meantime.)

Thanks for the effort! 🏆

[rpkilby]

It should be possible to do this without any significant reorganization - just some config changes and moving runtests.py into tests. My laptop is out of juice for the evening - I'll whip this up tomorrow.

Note to self, will need to usedevelop for builds to retain coverage stats. dist build will be simplified, as we can remove the --no-pkgroot hackery.

[codecov-io]

Codecov Report

Merging #6139 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #6139   +/-   ##
=======================================
  Coverage   96.18%   96.18%           
=======================================
  Files         128      128           
  Lines       17624    17624           
  Branches     1459     1459           
=======================================
  Hits        16951    16951           
  Misses        465      465           
  Partials      208      208

[rpkilby]

I was wrong. Running the test suite from tests only solves half the issue. This doesn't fix dependency installation, as python -m adds the current directory (the package root) and picks up its .egg-info directory. The simplest fix is to just delete the metadata.