$ git clone -n https://src.fedoraproject.org/rpms/kf6-kholidays.git /var/lib/mock/f42-build-side-1-3582679-46886/root/chroot_tmpdir/scmroot/kf6-kholidays
Cloning into '/var/lib/mock/f42-build-side-1-3582679-46886/root/chroot_tmpdir/scmroot/kf6-kholidays'...
$ git fetch origin 20b3190ab1ff3473397b939390892fbd7e7854cd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-kholidays
 * [new ref]         20b3190ab1ff3473397b939390892fbd7e7854cd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 20b3190 6.16.0