$ git clone -n https://src.fedoraproject.org/rpms/golang-github-google-cmp.git /var/lib/mock/f38-build-side-42-init-devel-588191-26120/root/chroot_tmpdir/scmroot/golang-github-google-cmp
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-588191-26120/root/chroot_tmpdir/scmroot/golang-github-google-cmp'...
$ git fetch origin 9cbf0976c5593a7d56269b812525102422c2010d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-google-cmp
 * [new ref]         9cbf0976c5593a7d56269b812525102422c2010d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9cbf097 Update to 0.5.9. Fixes rhbz#2125343.