Prior to this commit, pythonRelaxDeps would only support removing
version constraints from "Requires-Dist" lines formatted in a particular
way ("foo (>= 1.2.3)"). This way is deprecated as per PyPA Core Metadata
Specs v2.1 [1]:
> Tools parsing the format should accept optional parentheses around
> this, but tools generating it should not use parentheses.
Additionally, a "Requires-Dist" dependency specification can contain
other metadata than just package name and version (extra names,
environment marker). These were being silently dropped by the prior
version of pythonRelaxDeps, or the version could not be relaxed.
The actual grammar is defined in PEP 508 [2]. Our tool of choice here is
sed extended regexps, so there's only so much we can do to be correct
with this parser. The regexp implemented in this commit makes an attempt
at supporting [extra] names, ; env_markers, as well as version specs
without parentheses. There are still unsupported features (URL specs) as
well as unhandled edge cases, but at some point trying to make the
regexp better is bound to awake ZALGO [3].
[1] https://packaging.python.org/en/latest/specifications/core-metadata/#requires-dist-multiple-use
[2] https://peps.python.org/pep-0508/#grammar
[3] https://stackoverflow.com/a/1732454/179806
stdenv is included in the package set. It does not provide a Python
module however and was therefore catched by the test. Because we do need
it we provide an exception for it.
This adds a test to ensure no new uses of `buildPythonApplication` can
be added to `python-packages.nix`.
Python packages can be grouped into two groups: 1) applications and 2)
packages providing importable modules. In `python-packages.nix` we only
want to have 2). 1) should be in the top-level package set.
To achieve this, all setup hooks need to be marked as being a setup hook.
For the setup hooks in the Python packages set this is done by creating
a new builder, `makePythonHook`.
Because there were issues with splicing, the file importing all the hooks
is converted to an extension. All non-packages were moved out of `python-packages.nix`
into `python-packages-base.nix`. The `keep` argument to `makeScopeWithSplicing
was cleaned up as well; there is no need to keep this one manually in sync
reducing the risk of breaking cross-compilation.
