anchor.diff:          export HOME=$TMPDIR
           cd ${name}
           npm --registry http://www.example.com --nodedir=${nodeSources} ${npmFlags} ${stdenv.lib.optionalString production "--production"} rebuild
  -        npm --registry http://www.example.com --nodedir=${nodeSources} ${npmFlags} ${stdenv.lib.optionalString production "--production"} install
  +        
  +        ${stdenv.lib.optionalString (!dontNpmInstall) ''
  +          npm --registry http://www.example.com --nodedir=${nodeSources} ${npmFlags} ${stdenv.lib.optionalString production "--production"} install
  +        ''}
           
           # Create symlink to the deployed executable folder, if applicable
           if [ -d "$out/lib/node_modules/.bin" ]
  
positive.code:       name = "node-shell-${name}-${version}";
        
        buildInputs = [ python nodejs ] ++ stdenv.lib.optional (stdenv.isLinux) utillinux ++ args.buildInputs or [];
        buildCommand = "true";
        
        # Provide the dependencies in a development shell through the NODE_PATH environment variable
        shellHook = stdenv.lib.optionalString (dependencies != []) ''
  
negative.code:           
            export HOME=$TMPDIR
            npm --registry http://www.example.com --nodedir=${nodeSources} ${npmFlags} ${stdenv.lib.optionalString production "--production"} rebuild
            
            ${stdenv.lib.optionalString (!dontNpmInstall) ''
              npm --registry http://www.example.com --nodedir=${nodeSources} ${npmFlags} ${stdenv.lib.optionalString production "--production"} install
            ''}
          '';
        };
      in
  