anchor.diff:      { mkDerivation = args: stdenv.mkDerivation (args // {
           dontDisableStatic = true;
           configureFlags =
  -          (if args ? configureFlags then toString args.configureFlags else "")
  +          toString args.configureFlags or ""
             + " --enable-static --disable-shared";
         });
       } // {inherit fetchurl;};
  
positive.code:           pkg = stdenv.mkDerivation args;
            drv = builtins.unsafeDiscardStringContext pkg.drvPath;
            license =
              if pkg ? meta && pkg.meta ? license then
                pkg.meta.license
              else if pkg ? outputHash then
                # Fixed-output derivations such as source tarballs usually
                # don't have licensing information, but that's OK.
                null
              else
                builtins.trace
                  "warning: ${drv} lacks licensing information" null;
  
            validate = arg:
              if licensePred license then arg
  
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 {
  