anchor.diff: -{ stdenv, fetchurl, bash, firefox, perl, unzipNLS, xorg }:
  +{ stdenv, fetchurl, fetchpatch, bash, firefox, perl, unzipNLS, xorg }:
   
   let
   
  
positive.code: 
    nativeBuildInputs = [ perl unzipNLS ];
  
    inherit bash firefox;
  
    phases = "unpackPhase installPhase fixupPhase";
  
  
negative.code:     url = "https://download.zotero.org/extension/zotero-${version}.xpi";
      sha256 = "02h2ja08v8as4fawj683rh5rmxsjf5d0qmvqa77i176nm20y5s7s";
    };
  
    firefox' = stdenv.lib.overrideDerivation (firefox) (attrs: {
      patches = [ (fetchpatch {
        url = "https://hg.mozilla.org/releases/mozilla-beta/raw-rev/0558da46f20c";
        sha256 = "08ibp7hny78x8ywfvrh56z90kf8fjpf04mibdlrwkw4f1vgm3fc3";
        name = "fix-external-xpi-loader";
      }) ];
    });
  
    version = "4.0.28";
  
  