$ git clone -n https://src.fedoraproject.org/rpms/golang-github-burntsushi-graphics.git /var/lib/mock/f41-build-1421880-23566/root/chroot_tmpdir/scmroot/golang-github-burntsushi-graphics
Cloning into '/var/lib/mock/f41-build-1421880-23566/root/chroot_tmpdir/scmroot/golang-github-burntsushi-graphics'...
$ git fetch origin b96518228ac525f300e422423b8e1e53760e9a29:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-burntsushi-graphics
 * [new ref]         b96518228ac525f300e422423b8e1e53760e9a29 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b965182 Fix FTBFS