anchor.diff:            license = lib.licenses.free;
           };
         }) {};
  +    vdiff = callPackage ({ elpaBuild, emacs, fetchurl, hydra, lib }: elpaBuild {
  +        pname = "vdiff";
  +        version = "0.2.3";
  +        src = fetchurl {
  +          url = "https://elpa.gnu.org/packages/vdiff-0.2.3.el";
  +          sha256 = "197wszzhm2kbfvvlg3f0dzfs3lf4536yq5fd67k2rycj421fr9qz";
  +        };
  +        packageRequires = [ emacs hydra ];
  +        meta = {
  +          homepage = "https://elpa.gnu.org/packages/vdiff.html";
  +          license = lib.licenses.free;
  +        };
  +      }) {};
       vlf = callPackage ({ elpaBuild, fetchurl, lib }: elpaBuild {
           pname = "vlf";
           version = "1.7";
  
positive.code:     test-simple = callPackage ({ cl-lib ? null, elpaBuild, fetchurl, lib }:
      elpaBuild {
          pname = "test-simple";
          version = "1.2.0";
          src = fetchurl {
            url = "https://elpa.gnu.org/packages/test-simple-1.2.0.el";
            sha256 = "1j97qrwi3i2kihszsxf3y2cby2bzp8g0zf6jlpdix3dinav8xa3b";
          };
          packageRequires = [ cl-lib ];
          meta = {
  
negative.code:     other-frame-window = callPackage ({ elpaBuild, emacs, fetchurl, lib }:
      elpaBuild {
          pname = "other-frame-window";
          version = "1.0.3";
          src = fetchurl {
            url = "https://elpa.gnu.org/packages/other-frame-window-1.0.3.el";
            sha256 = "0vq1zfsdnxdjvmb7lkjyax27kfv0rw0141rd5fjnl6ap9yjwpxkv";
          };
          packageRequires = [ emacs ];
          meta = {
  