$ git clone -n https://src.fedoraproject.org/rpms/libxcb.git /var/lib/mock/f31-build-47696-26959/root/chroot_tmpdir/scmroot/libxcb
Cloning into '/var/lib/mock/f31-build-47696-26959/root/chroot_tmpdir/scmroot/libxcb'...
$ git reset --hard cbfce27faff1e5e5a31bb5a430cdd7028284a09e
HEAD is now at cbfce27 - Rebuilt for https://fedoraproject.org/wiki/Fedora_30_Mass_Rebuild