$ git clone -n https://src.fedoraproject.org/rpms/R-IRanges.git /var/lib/mock/f45-build-5889-345/root/chroot_tmpdir/scmroot/R-IRanges
Cloning into '/var/lib/mock/f45-build-5889-345/root/chroot_tmpdir/scmroot/R-IRanges'...
$ git fetch origin 16a297cc631b083fdcf6541cb77d1ee80e3bec2f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-IRanges
 * [new ref]         16a297cc631b083fdcf6541cb77d1ee80e3bec2f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 16a297c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild