$ git clone -n https://src.fedoraproject.org/rpms/R-Rmpfr.git /var/lib/mock/f31-build-76449-31415/root/thebuilddir/tmp/scmroot/R-Rmpfr
Cloning into '/var/lib/mock/f31-build-76449-31415/root/thebuilddir/tmp/scmroot/R-Rmpfr'...
$ git reset --hard 712dd5e4cb3fa0e0ce76d99027f526080ac31344
HEAD is now at 712dd5e - Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild