A very ugly decision: in order to register the diff between 0.57 and 0.60
releases of Meson in Nixpkgs, I copied the whole directory before actually write
it by hand.
Meson is a delicate package. It needs some patches to properly work in Nixpkgs
and many packages have it as a dependency, from many small applications to
systemd (yay, mass rebuilds in sight!). Updating it is not a trivial and
harmless task.
Therefore, I took the paranoid way and encapsulate the current version in a
subdir, instead of the regular write-over procedure. This way, at the best we
can just remove the whole dir in the future, and at the worse we just maintain
duplicated code.
continuation of #109595
pkgconfig was aliased in 2018, however, it remained in
all-packages.nix due to its wide usage. This cleans
up the remaining references to pkgs.pkgsconfig and
moves the entry to aliases.nix.
python3Packages.pkgconfig remained unchanged because
it's the canonical name of the upstream package
on pypi.
This reverts commit c778945806.
I believe this is exactly what brings the staging branch into
the right shape after the last merge from master (through staging-next);
otherwise part of staging changes would be lost
(due to being already reachable from master but reverted).
Meson allows projects to set `build_rpath` property, containing paths
that will be added during build but will be removed when installing.
When Meson removes build_rpath from `DT_RUNPATH` entry, it just writes
the shorter ␀-terminated new rpath over the old one to reduce
the risk of potentially breaking the ELF files
(when the linker does string de-duplication or something).
But this can cause much bigger problem for Nix, as it can produce
cut-in-half-by-␀ store path references.
For example, in systemd’s libudev, it was removing three `$ORIGIN`-relative paths from
$ORIGIN/../libsystemd:$ORIGIN/../basic:$ORIGIN/../shared:…␀
resulting in the following `DT_RUNPATH` entry:
…␀store/v589pqjhvxrj73g3r0xb41yr84z5pwb7-gcc-9.3.0-lib/lib␀
We previously handled this in `fix-rpath.patch` but the method we prevent
Meson from removing paths added to rpath through `NIX_LDFLAGS` was changed
during 0.55.0 update and I forgot about this second purpose of the patch.
Let’s re-add this clearing code, as it worked without issues for a long time.
The old `CC=.. CXX= .. meson ...` env var hack I removed in
3c00ca03a2 had a side effect of ensuring
that Meson always had access to a native C compiler, which unforunately
it expects in most cases. Thankfully, that will be fixed soon.
The cross file is added in the `mkDerivation`. It isn't nice putting
build tool-specific stuff here, but our current architecture gives us
little alternative.
See comment in code and the PR it references,
https://github.com/mesonbuild/meson/pull/6827, for details.
We can remove entries from the cross file because they will be gotten
from env vars now.
