$ git clone -n https://src.fedoraproject.org/rpms/R-R2HTML.git /var/lib/mock/f45-build-5891-345/root/chroot_tmpdir/scmroot/R-R2HTML
Cloning into '/var/lib/mock/f45-build-5891-345/root/chroot_tmpdir/scmroot/R-R2HTML'...
$ git fetch origin 725b2532835c80ee5c1fe3841b235b446ddc990b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-R2HTML
 * [new ref]         725b2532835c80ee5c1fe3841b235b446ddc990b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 725b253 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild