anchor.diff:      pname = "with-editor";
       version = magit.version;
       src = magit.src;
  -    packageRequires = [ dash ];
  +    packageRequires = [ async dash ];
       fileSpecs = [ "Documentation/with-editor.texi" "lisp/with-editor.el" ];
       meta = { license = gpl3Plus; };
     };
  
positive.code: 
    async = melpaBuild rec {
      pname   = "async";
      version = "1.2";
      src = fetchFromGitHub {
        owner  = "jwiegley";
        repo   = "emacs-async";
        rev    = "v${version}";
        sha256 = "1j6mbvvbnm2m1gpsy9ipxiv76b684nn57yssbqdyiwyy499cma6q";
      };
      meta = {
        description = "Asynchronous processing in Emacs";
  
negative.code:     };
    };
  
    hydra = melpaBuild rec {
      pname   = "hydra";
      version = "0.13.3";
      src = fetchFromGitHub {
        owner  = "abo-abo";
        repo   = pname;
        rev    = version;
        sha256 = "08iw95lyizcyf6cjl37fm8wvay0vsk9758pk9gq9f2xiafcchl7f";
      };
      meta = { license = gpl3Plus; };
    };
  
    ibuffer-vc = melpaBuild rec {
      pname   = "ibuffer-vc";
      version = "0.10";
  