nixpkgs/pkgs/misc/vim-plugins/vim2nix/additional-nix-code/deoplete-go

    buildInputs = [ python3 ]; 
    buildPhase = ''
      pushd ./rplugin/python3/deoplete/ujson
      python3 setup.py build --build-base=$PWD/build --build-lib=$PWD/build
      popd
      find ./rplugin/ -name "ujson*.so" -exec mv -v {} ./rplugin/python3/ \;
    '';