fix: release py-matplotlib from require: %clang

[wdconinc]

Briefly, what does this PR introduce?

This PR allows py-matplotlib to be compiled with gcc again as well. There are some issues with concretization when we have the clang constraint, so I'm hoping the issue with gcc and LTO is resolved by now...

[Copilot]

Pull request overview

This PR removes the compiler-specific constraint requiring py-matplotlib to be built with Clang. The change allows py-matplotlib to use the default GCC compiler, assuming that previous issues with GCC and LTO have been resolved.

Key Changes

• Removed the %clang requirement for py-matplotlib from packages.yaml
• py-matplotlib will now default to GCC compilation as per the global compiler preference

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[veprbl]

Looked like CI failures are irrelevant.

[wdconinc]

Looked like CI failures are irrelevant.

Actually, I think they are relevant. I don't know why it wants to build a new llvm because of this change.

[veprbl]

Please give a link, I only saw a few docker socket ones.

[wdconinc]

Please give a link, I only saw a few docker socket ones.

Maybe I'm thinking of another branch. Will post a link if it repeats.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[wdconinc]

Please give a link, I only saw a few docker socket ones.

Seems fine now. I thought it previously wanted to build a whole new llvm for iwyu in this PR...

[veprbl]

It's not happy:

ImportError: /opt/local/lib/python3.13/site-packages/matplotlib/_path.cpython-313-x86_64-linux-gnu.so: undefined symbol: _ZN3agg10curve3_div4initEdddddd

[wdconinc]

It's not happy:

ImportError: /opt/local/lib/python3.13/site-packages/matplotlib/_path.cpython-313-x86_64-linux-gnu.so: undefined symbol: _ZN3agg10curve3_div4initEdddddd

Yeah, that was the original reason for %clang... So, not fixed then, clearly.

This is an underlying issue in meson. It uses the wrong (mismatched) ar when linking with lto (which the spack build enforces).

• no clear place to patch meson to do this better
• could make lto optional instead of enforcing for GCC
• could set $AR to the correct gcc-ar in spack

Leaving PR open for tracking.

[wdconinc]

This probably needs under the extra_attributes for GCC:

        environment:
          set:
            GCC_AR: /usr/bin/gcc-ar-14

Refs:

• Prefer $GCC_AR over $AR with gcc? mesonbuild/meson#13324
• Installation issue: py-matplotlib@3.9:%gcc@14:, undefined symbol: _ZN3agg10curve3_div4initEdddddd spack/spack-packages#1068

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.