$ git clone -n https://src.fedoraproject.org/rpms/R-NISTunits.git /var/lib/mock/f45-build-5895-345/root/chroot_tmpdir/scmroot/R-NISTunits
Cloning into '/var/lib/mock/f45-build-5895-345/root/chroot_tmpdir/scmroot/R-NISTunits'...
$ git fetch origin 618cbb9ba00623e1d18f0aa7d68967faeb994a3e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-NISTunits
 * [new ref]         618cbb9ba00623e1d18f0aa7d68967faeb994a3e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 618cbb9 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild