anchor.diff:     *
      * Example:
      * # Writes contents of files to /nix/store/<store path>
  -   * concatdScript "my-file" [ file1 file2 ]
  +   * concatScript "my-file" [ file1 file2 ]
      *
     */
     concatScript = name: files: concatTextFile { inherit name files; executable=true; };
  
positive.code:    *   name = "my-file";
     *   files = [ drv1 "${drv2}/path/to/file" ];
     * }
     * # See also the `concatdText` helper function below.
     *
     * # Writes executable my-file to /nix/store/<store path>/bin/my-file
     * concatTextFile {
     *   name = "my-file";
     *   files = ''
     *     Contents of File
     *   '';
     *   executable = true;
     *   destination = "/bin/my-file";
     * }
  
negative.code:     runCommandLocal name
        { inherit files executable checkPhase meta destination; }
        ''
          file=$out$destination
          mkdir -p "$(dirname "$file")"
          cat $files > "$file"
  
          (test -n "$executable" && chmod +x "$file") || true
          eval "$checkPhase"
        '';
  
  
  