$ git clone -n https://src.fedoraproject.org/rpms/calc.git /var/lib/mock/f40-build-2217236-52543/root/chroot_tmpdir/scmroot/calc
Cloning into '/var/lib/mock/f40-build-2217236-52543/root/chroot_tmpdir/scmroot/calc'...
$ git fetch origin a939790aeebd4136bb1bc832e01068de52c5fe85:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/calc
 * [new ref]         a939790aeebd4136bb1bc832e01068de52c5fe85 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a939790 new minor upstream release 2.15.0.2