$ git clone -n https://src.fedoraproject.org/rpms/R-RMariaDB.git /var/lib/mock/f45-build-5919-345/root/chroot_tmpdir/scmroot/R-RMariaDB
Cloning into '/var/lib/mock/f45-build-5919-345/root/chroot_tmpdir/scmroot/R-RMariaDB'...
$ git fetch origin d753129cbbda187846fde5567278ae1fce1e6055:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-RMariaDB
 * [new ref]         d753129cbbda187846fde5567278ae1fce1e6055 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d753129 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild