$ git clone -n https://src.fedoraproject.org/rpms/extremetuxracer.git /var/lib/mock/f42-build-side-1-3568063-46743/root/chroot_tmpdir/scmroot/extremetuxracer
Cloning into '/var/lib/mock/f42-build-side-1-3568063-46743/root/chroot_tmpdir/scmroot/extremetuxracer'...
$ git fetch origin 6cf425f7fdff511711302d8154d399a1bcb01ce4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/extremetuxracer
 * [new ref]         6cf425f7fdff511711302d8154d399a1bcb01ce4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6cf425f 0.8.4