In https://github.com/NixOS/nixpkgs/issues/139292 we found out that
pytest leaves pytest-generated bytecode in install directory
(as tests are ran after install). That bytecode is:
- non-deterministic (was copied from cpython before cpython got
support for deterministic bytecode)
- unneeded after test run
The change cleans bytecode up and provides a hook variable to avoid it
if needed.
Tested on `python39Packages.pytest-xdist` and `python27Packages.flaky` as:
$ nix build -f. python39Packages.pytest-xdist
$ nix build -f. python39Packages.pytest-xdist --rebuild
$ nix build -f. python27Packages.flaky
$ nix build -f. python27Packages.flaky --rebuild
Closes: https://github.com/NixOS/nixpkgs/issues/139292
Sergei Trofimovich
f0bb568b74