$ git clone -n https://src.fedoraproject.org/rpms/zycore-c.git /var/lib/mock/f45-build-39421-735/root/chroot_tmpdir/scmroot/zycore-c
Cloning into '/var/lib/mock/f45-build-39421-735/root/chroot_tmpdir/scmroot/zycore-c'...
$ git fetch origin c864314c0dc7ca752f2866d585d9e05a29a6de6c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/zycore-c
 * [new ref]         c864314c0dc7ca752f2866d585d9e05a29a6de6c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c864314 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild