$ git clone -n https://src.fedoraproject.org/rpms/mesa.git /var/lib/mock/f41-build-850527-165462/root/chroot_tmpdir/scmroot/mesa
Cloning into '/var/lib/mock/f41-build-850527-165462/root/chroot_tmpdir/scmroot/mesa'...
$ git fetch origin 6fbaafcfe7e30e3368d640cd42e2c10ba738acd7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mesa
 * [new ref]         6fbaafcfe7e30e3368d640cd42e2c10ba738acd7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6fbaafc Retire OpenMAX suppot