$ git clone -n https://src.fedoraproject.org/rpms/R-polynom.git /var/lib/mock/f45-build-6318-347/root/chroot_tmpdir/scmroot/R-polynom
Cloning into '/var/lib/mock/f45-build-6318-347/root/chroot_tmpdir/scmroot/R-polynom'...
$ git fetch origin 54a960d641351304912d0f881c800e33ca02f127:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-polynom
 * [new ref]         54a960d641351304912d0f881c800e33ca02f127 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 54a960d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild