$ git clone -n https://src.fedoraproject.org/rpms/retrace-server.git /var/lib/mock/f41-build-1189041-22177/root/chroot_tmpdir/scmroot/retrace-server
Cloning into '/var/lib/mock/f41-build-1189041-22177/root/chroot_tmpdir/scmroot/retrace-server'...
$ git fetch origin 6cd5a23d9a160c270c30649798ce02feb571a5ed:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/retrace-server
 * [new ref]         6cd5a23d9a160c270c30649798ce02feb571a5ed -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6cd5a23 Drop call to marshalparser