$ git clone -n https://src.fedoraproject.org/rpms/R-FMStable.git /var/lib/mock/f31-build-49619-27317/root/chroot_tmpdir/scmroot/R-FMStable
Cloning into '/var/lib/mock/f31-build-49619-27317/root/chroot_tmpdir/scmroot/R-FMStable'...
$ git reset --hard c2a6c19a28cd386671811d2a050defed581b84c6
HEAD is now at c2a6c19 - Rebuilt for https://fedoraproject.org/wiki/Fedora_30_Mass_Rebuild