anchor.diff:  
   in
   
  -# We need all these X libraries when building AWT with GTK+.
  -assert x11Support -> (filter (x: x == null) ([ gtk2 libart_lgpl ] ++ xlibs)) == [];
  -
   stdenv.mkDerivation ({
     name = "${name}${if stripped then "" else "-debug"}-${version}" + crossNameAddon;
   
  
positive.code: , langC ? true, langCC ? true, langFortran ? false
  , langObjC ? targetPlatform.isDarwin
  , langObjCpp ? targetPlatform.isDarwin
  , langJava ? false
  , langGo ? false
  , profiledCompiler ? false
  , staticCompiler ? false
  , enableShared ? true
  , texinfo ? null
  , perl ? null # optional, for texi2pod (then pod2man); required for Java
  , gmp, mpfr, libmpc, gettext, which
  , libelf                      # optional, for link-time optimizations (LTO)
  , isl ? null # optional, for the Graphite optimization framework.
  , zlib ? null, boehmgc ? null
  , zip ? null, unzip ? null, pkgconfig ? null
  , gtk2 ? null, libart_lgpl ? null
  , libX11 ? null, libXt ? null, libSM ? null, libICE ? null, libXtst ? null
  , libXrender ? null, xproto ? null, renderproto ? null, xextproto ? null
  , libXrandr ? null, libXi ? null, inputproto ? null, randrproto ? null
  , x11Support ? langJava
  , enableMultilib ? false
  , enablePlugin ? hostPlatform == buildPlatform # Whether to support user-supplied plug-ins
  , name ? "gcc"
  
negative.code: 
    CPATH = optionals (targetPlatform == hostPlatform) (makeSearchPathOutput "dev" "include" ([]
      ++ optional (zlib != null) zlib
      ++ optional (libpthread != null) libpthread
      ++ optional (libpthreadCross != null) libpthreadCross
  
  