reproduce:
        # https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools.git/commit/?id=cf36d63d7cc9a9770f69f44a10904e9fb0895fa9
        git remote add perf-tools https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools.git
        git fetch --no-tags perf-tools tmp.perf-tools
        git checkout cf36d63d7cc9a9770f69f44a10904e9fb0895fa9
        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