$ git clone -n https://src.fedoraproject.org/rpms/R-acepack.git /var/lib/mock/f45-build-5965-345/root/chroot_tmpdir/scmroot/R-acepack
Cloning into '/var/lib/mock/f45-build-5965-345/root/chroot_tmpdir/scmroot/R-acepack'...
$ git fetch origin 937fc92c9839331390647d895dfe3f93567ffa40:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-acepack
 * [new ref]         937fc92c9839331390647d895dfe3f93567ffa40 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 937fc92 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild