anchor.diff:          # These are added *after* the command-line flags, so we'll
           # always optimise for size.
           NIX_CFLAGS_COMPILE =
  -          (if args ? NIX_CFLAGS_COMPILE then args.NIX_CFLAGS_COMPILE else "")
  -          + " -Os -s";
  +          args.NIX_CFLAGS_COMPILE or "" + " -Os -s";
   
           configureFlags =
  -          (if args ? configureFlags then args.configureFlags else "")
  -          + " --disable-shared"; # brrr...
  +          args.configureFlags or "" + " --disable-shared"; # brrr...
   
           NIX_GCC = runCommand "klibc-wrapper" {} ''
             mkdir -p $out/bin
  
positive.code:   # for other dependencies.
    overrideInStdenv = stdenv: pkgs: stdenv //
      { mkDerivation = args: stdenv.mkDerivation (args //
          { buildInputs = (if args ? buildInputs then args.buildInputs else []) ++ pkgs; }
        );
      };
  
  
negative.code:         # These are added *after* the command-line flags, so we'll
          # always optimise for size.
          NIX_CFLAGS_COMPILE =
            args.NIX_CFLAGS_COMPILE or ""
            + " -Os -s -D_BSD_SOURCE=1";
  
          configureFlags =
            args.configureFlags or ""
            + " --disable-shared"; # brrr...
  
          NIX_GCC = import ../build-support/gcc-wrapper {
  