$ git clone -n https://src.fedoraproject.org/rpms/libfastjson.git /var/lib/mock/f31-build-68736-30220/root/thebuilddir/tmp/scmroot/libfastjson
Cloning into '/var/lib/mock/f31-build-68736-30220/root/thebuilddir/tmp/scmroot/libfastjson'...
$ git reset --hard 439b5b1348cfe4eaa0dcede23da46416d3a4abe2
HEAD is now at 439b5b1 - Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild