Python package sets can be overridden by overriding an interpreter
and passing in `packageOverrides = self: super: {...};`. This is fine
in case you need a single interpreter, however, it does not help you
when you want to override all sets.
With this change it is possible to override all sets at once by
appending a list of "extensions" to `pythonPackagesExtensions`.
From reading the implementation you might wonder why a list is used, and
not
`lib.composeExtensions`? The reason is the latter requires knowledge of
the library function. This approach should be easier for most users
as it is similar to how we append to lists of e.g. inputs or patches
when overriding a derivation.
The PEP600 standard gives Python's naming scheme for various
architectures; it follows the convention which was in use by Fedora in
2014. According to PEP600, the architecture name for Power PC is
`ppc64le`, not `powerpc64le`. This is also how python3 declares its
"supported wheels" under Debian on PowerPC, as checked with `pip debug
--verbose`
$ pip debug --verbose | grep powerpc
$ pip debug --verbose | grep ppc | head
cp39-cp39-manylinux_2_31_ppc64le
cp39-cp39-manylinux_2_30_ppc64le
cp39-cp39-manylinux_2_29_ppc64le
cp39-cp39-manylinux_2_28_ppc64le
cp39-cp39-manylinux_2_27_ppc64le
cp39-cp39-manylinux_2_26_ppc64le
cp39-cp39-manylinux_2_25_ppc64le
cp39-cp39-manylinux_2_24_ppc64le
cp39-cp39-manylinux_2_23_ppc64le
Let's adjust the `pythonHostPlatform` expression in
cpython/default.nix to pass the architecture using the naming scheme
Python expects.
Verified on a Raptor Computing Systems Talos II. Without this commit,
PyQt5 fails to build, failing with "unsupported wheel". With this
commit, it builds successfully.
Every package should have a maintainer and we should not throw it away if we arleady have one.
Also in reality the maintainer of python3 is also the one of python3-minimal
GCC does not come with a `libgcc_eh.a` for the target platform if
it was built without `--enable-shared`. That flag was removed with
c6dd11ca39, meaning we should no longer
attempt to link against that lib.
We have a common pattern here in nixpkgs for Python applications: when a
Python package ships with either a requirements.txt or setup.py file, we
generally end up having to modify its version restriction, otherwise we have
build failures since we package only one specific version of each package
normally.
However, this end up being done in a completely ad-hoc way: some people
use substituteInPlace, some others use sed, others uses patches, etc.
In many cases, the code ends up being buggy, so it may work in one
version and breaks on the next one. We can instead implement one
standard way of doing this, and trying to be a correct as possible.
So this is what this commit does: it implements a new build hook, that
when called will automatically patch the wheel file. This is one of the
most generic ways to patch Python dependencies, and should work in
multiple cases.
Noticed option globbing when tried to enable parallelism by default
locally for most packages by default. python3Packages.yt-dlp failed as:
python3.9-yt-dlp> /nix/store/5mywvxdjkk1q6srwwwgdkzc37ibla801-python3.9-setuptools-61.2.0/lib/python3.9/site-packages/setuptools/dist.py:516: UserWarning: Normalizing '2022.04.08' to '2022.4.8'
python3.9-yt-dlp> warnings.warn(tmpl.format(**locals()))
python3.9-yt-dlp> invalid command name 'build_lazy_extractors--parallel'
The change adds leading whitespace everywhere where options might
already be present.
Overriding the interpreters did not work correctly. When overriding
packages would end up twice in the build time closure: one corresponding
to the overridden interpreter and one corresponding to the original
interpreter. The reason is that the override was not applied to the
interpreters in the spliced package sets.
