$ git clone -n https://src.fedoraproject.org/rpms/R-measurements.git /var/lib/mock/f45-build-6219-347/root/chroot_tmpdir/scmroot/R-measurements
Cloning into '/var/lib/mock/f45-build-6219-347/root/chroot_tmpdir/scmroot/R-measurements'...
$ git fetch origin 95952aa244f8dee46092f49a2364a1542eb4847a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-measurements
 * [new ref]         95952aa244f8dee46092f49a2364a1542eb4847a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 95952aa Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild