$ git clone -n https://src.fedoraproject.org/rpms/golang-github-saracen-walker.git /var/lib/mock/f41-build-1036350-18724/root/chroot_tmpdir/scmroot/golang-github-saracen-walker
Cloning into '/var/lib/mock/f41-build-1036350-18724/root/chroot_tmpdir/scmroot/golang-github-saracen-walker'...
$ git fetch origin 968b4773522197968e4f1b64a49420c4ec3abee8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-saracen-walker
 * [new ref]         968b4773522197968e4f1b64a49420c4ec3abee8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 968b477 Fix FTBFS