reproduce:
        # https://github.com/zen-kernel/zen-kernel/commit/dc4e3e63538d51b8adc868b401be163e4932884a
        git remote add zen https://github.com/zen-kernel/zen-kernel
        git fetch --no-tags zen 6.12/ntsync5
        git checkout dc4e3e63538d51b8adc868b401be163e4932884a
        make W=1 O=/tmp/kselftest headers
        make W=1 O=/tmp/kselftest -C tools/testing/selftests
        make W=1 O=/tmp/kselftest -C tools/testing/selftests/bpf