$ git clone -n https://src.fedoraproject.org/rpms/mesa.git /var/lib/mock/f40-build-1951433-25190/root/chroot_tmpdir/scmroot/mesa
Cloning into '/var/lib/mock/f40-build-1951433-25190/root/chroot_tmpdir/scmroot/mesa'...
$ git fetch origin 2f038b212a4dc122f370102677d0fe1144ace004:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mesa
 * [new ref]         2f038b212a4dc122f370102677d0fe1144ace004 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2f038b2 Remove unused patch