$ git clone -n https://src.fedoraproject.org/rpms/gnucash.git /var/lib/mock/f41-build-813549-148686/root/chroot_tmpdir/scmroot/gnucash
Cloning into '/var/lib/mock/f41-build-813549-148686/root/chroot_tmpdir/scmroot/gnucash'...
$ git fetch origin fa1de1646b39491e052999cb8cc682cdabc61aaa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnucash
 * [new ref]         fa1de1646b39491e052999cb8cc682cdabc61aaa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fa1de16 5.8