$ git clone -n https://src.fedoraproject.org/rpms/R-mapproj.git /var/lib/mock/f45-build-6202-347/root/chroot_tmpdir/scmroot/R-mapproj
Cloning into '/var/lib/mock/f45-build-6202-347/root/chroot_tmpdir/scmroot/R-mapproj'...
$ git fetch origin 21e17b9d7ae31651c2cd6b4112d6ce04cc76a399:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-mapproj
 * [new ref]         21e17b9d7ae31651c2cd6b4112d6ce04cc76a399 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21e17b9 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild