anchor.diff:  
     src = fetchurl {
       url = "mirror://gnome/sources/atk/${channel}/${name}.tar.xz";
  -    sha256Url = "mirror://gnome/sources/atk/${channel}/${name}.sha256sum";
  +    hashOutput = false;
       inherit (source) sha256;
     };
   
  
positive.code: 
  let
    inherit (stdenv.lib)
      enFlag;
  
    source = (import ./sources.nix { })."${channel}";
  in
  
negative.code:     "--enable-glibtest"
      "--enable-nls"
      "--enable-rpath"
      "--${boolEn (gobject-introspection != null)}-introspection"
      "--disable-gtk-doc"
      "--disable-gtk-doc-html"
      "--disable-gtk-doc-pdf"
    ];
  
    postInstall = "rm -rvf $out/share/gtk-doc";
  
    passthru = {
      srcVerification = fetchurl {
        inherit (src)
          outputHash
          outputHashAlgo
          urls;
        sha256Url = "https://download.gnome.org/sources/atk/"
          + "${channel}/${name}.sha256sum";
        failEarly = true;
      };
    };
  
    meta = with stdenv.lib; {
      description = "GTK+ & GNOME Accessibility Toolkit";
  