anchor.diff:  
   # build-tools
   , bootPkgs, alex, happy, hscolour
  -, autoconf, automake, coreutils, fetchurl, perl, python3, sphinx
  +, autoconf, autoreconfHook, automake, coreutils, fetchurl, fetchpatch, perl, python3, sphinx
   
   , libffi, libiconv ? null, ncurses
   
  
positive.code: 
    outputs = [ "out" "doc" ];
  
    postPatch = "patchShebangs .";
  
    # GHC is a bit confused on its cross terminology.
  
negative.code:   # masss-rebuild.
    crossConfig = true;
  
    nativeBuildInputs = [ alex autoconf autoreconfHook automake ghc happy hscolour perl python3 sphinx ];
  
    # For building runtime libs
    depsBuildTarget = toolsForTarget;
  