$ git clone -n https://src.fedoraproject.org/rpms/m1n1.git /var/lib/mock/f40-build-2255740-54263/root/chroot_tmpdir/scmroot/m1n1
Cloning into '/var/lib/mock/f40-build-2255740-54263/root/chroot_tmpdir/scmroot/m1n1'...
$ git fetch origin fb67c624836dc90fe4d8d9e0af194f80c029935d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/m1n1
 * [new ref]         fb67c624836dc90fe4d8d9e0af194f80c029935d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fb67c62 Update to 1.4.11