$ git clone -n https://src.fedoraproject.org/rpms/90-Second-Portraits.git /var/lib/mock/f40-build-2124524-50775/root/chroot_tmpdir/scmroot/90-Second-Portraits
Cloning into '/var/lib/mock/f40-build-2124524-50775/root/chroot_tmpdir/scmroot/90-Second-Portraits'...
$ git fetch origin a6d9acd1e56bd67dff6056da84e08e96c5ed8b1f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/90-Second-Portraits
 * [new ref]         a6d9acd1e56bd67dff6056da84e08e96c5ed8b1f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a6d9acd Licensing fixes