$ git clone -n https://src.fedoraproject.org/rpms/R-expm.git /var/lib/mock/f29-build-1175-484/root/thebuilddir/tmp/scmroot/R-expm
Cloning into '/var/lib/mock/f29-build-1175-484/root/thebuilddir/tmp/scmroot/R-expm'...
$ git reset --hard d1727186eed32e152e13e907484dddc1d522b44b
HEAD is now at d172718 - Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild