$ git clone -n https://src.fedoraproject.org/rpms/golang-x-image.git /var/lib/mock/f38-build-side-42-init-devel-676676-26690/root/chroot_tmpdir/scmroot/golang-x-image
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-676676-26690/root/chroot_tmpdir/scmroot/golang-x-image'...
$ git fetch origin f94a3d8f63577e09b45113306f5e8dee30922b1c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-x-image
 * [new ref]         f94a3d8f63577e09b45113306f5e8dee30922b1c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f94a3d8 Update to latest version (#2173328)