Presence of multiple versions in /usr/lib/gcc/x86_64-linux-gnu in sparc images causes clang warning

In GitLab by @nathanchance on Oct 8, 2025, 01:41 GMT+1:

In the sparc_clang-nightly image, there are two versions of /usr/lib/gcc/x86_64-linux-gnu installed, which ends up causing a benign but occasionally fatal warning (due to -Werror).

$ podman run --rm -ti docker.io/tuxmake/sparc_clang-nightly
root@f97719560aa8:/# clang -fsyntax-only -x c /dev/null
clang: warning: future releases of the clang compiler will prefer GCC installations containing libstdc++ include directories; '/usr/lib/gcc/x86_64-linux-gnu/14' would be chosen over '/usr/lib/gcc/x86_64-linux-gnu/15' [-Wgcc-install-dir-libstdcxx]
root@f97719560aa8:/# ls -l /usr/lib/gcc/x86_64-linux-gnu
total 0
drwxr-xr-x 1 root root  224 Oct  7 03:15 14
drwxr-xr-x 1 root root 1136 Oct  7 03:15 15

Other images such as x86_64_clang-nightly do not have this issue.

$ podman run --rm -ti docker.io/tuxmake/x86_64_clang-nightly
root@94c32cd7bae8:/# ls -l /usr/lib/gcc/x86_64-linux-gnu
total 0
drwxr-xr-x 1 root root 196 Apr 30 03:01 12

Migrated from GitLab: https://gitlab.com/Linaro/tuxmake/-/issues/226

Start by locating how the sparc_clang-nightly image is assembled and compare it with x86_64_clang-nightly. Reproduce the warning with the shown podman command and inspect the installed GCC directories; done means the image no longer contains the conflicting versions or emits this warning.