$ git clone -n https://src.fedoraproject.org/rpms/R-gargle.git /var/lib/mock/f45-build-6131-346/root/chroot_tmpdir/scmroot/R-gargle
Cloning into '/var/lib/mock/f45-build-6131-346/root/chroot_tmpdir/scmroot/R-gargle'...
$ git fetch origin b0dc0e126a903b9dc809dc659cf9f7b5ccbf8c5e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-gargle
 * [new ref]         b0dc0e126a903b9dc809dc659cf9f7b5ccbf8c5e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b0dc0e1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild