$ git clone -n https://src.fedoraproject.org/rpms/golang-github-gobwas-ws.git /var/lib/mock/f45-build-11968-436/root/chroot_tmpdir/scmroot/golang-github-gobwas-ws
Cloning into '/var/lib/mock/f45-build-11968-436/root/chroot_tmpdir/scmroot/golang-github-gobwas-ws'...
$ git fetch origin c801b8cf280a8f5f711b267cbe12a293dea0b672:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-gobwas-ws
 * [new ref]         c801b8cf280a8f5f711b267cbe12a293dea0b672 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c801b8c rebuild