$ git clone -n https://github.com/xcp-ng-rpms/emulex-lpfc-alt.git /var/lib/mock/v8.3-incoming-10812-29326/root/chroot_tmpdir/scmroot/emulex-lpfc-alt
Cloning into '/var/lib/mock/v8.3-incoming-10812-29326/root/chroot_tmpdir/scmroot/emulex-lpfc-alt'...
$ git fetch origin 6d53d1e49ccca265a1947742e22350445e82bb34:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/emulex-lpfc-alt
 * [new ref]         6d53d1e49ccca265a1947742e22350445e82bb34 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6d53d1e Add BuildRequires gcc