anchor.diff:            license = lib.licenses.free;
           };
         }) {};
  -    xr = callPackage ({ elpaBuild, fetchurl, lib }:
  +    xr = callPackage ({ elpaBuild, emacs, fetchurl, lib }:
         elpaBuild {
           pname = "xr";
           ename = "xr";
  -        version = "1.13";
  -        src = fetchurl {
  -          url = "https://elpa.gnu.org/packages/xr-1.13.tar";
  -          sha256 = "1km4x92pii8c4bcimks4xzhmwpypdf183z0zh7raj062jz4jb74r";
  -        };
  -        packageRequires = [];
  +        version = "1.16";
  +        src = fetchurl {
  +          url = "https://elpa.gnu.org/packages/xr-1.16.tar";
  +          sha256 = "1s6pkbr7gkan0r9gfmix75m587d8cg6l11722v70zzgf2z9w2xg9";
  +        };
  +        packageRequires = [ emacs ];
           meta = {
             homepage = "https://elpa.gnu.org/packages/xr.html";
             license = lib.licenses.free;
  
positive.code:       elpaBuild {
          pname = "debbugs";
          ename = "debbugs";
          version = "0.21";
          src = fetchurl {
            url = "https://elpa.gnu.org/packages/debbugs-0.21.tar";
            sha256 = "1xx1wjfpsnwx2fpydqhwy9k1b5kjk8dqbkzf8lqaj9c4rvjbn50a";
          };
          packageRequires = [ emacs soap-client ];
          meta = {
  
negative.code:       elpaBuild {
          pname = "ada-mode";
          ename = "ada-mode";
          version = "7.0.1";
          src = fetchurl {
            url = "https://elpa.gnu.org/packages/ada-mode-7.0.1.tar";
            sha256 = "0iqninv4wf4ap8axk9m0gi39j3kq4jpbpdc8hczd34xrp83ml46a";
          };
          packageRequires = [ emacs uniquify-files wisi ];
          meta = {
  