anchor.diff:        (ifMinVer "0.6" "--enable-pic")
         (enableFeature runtimeCpuDetectBuild "runtime-cpudetect")
         "--enable-hardcoded-tables"
  +    ] ++
         (if multithreadBuild then (
            if stdenv.isCygwin then
  -           "--disable-pthreads --enable-w32threads"
  +           ["--disable-pthreads" "--enable-w32threads"]
            else # Use POSIX threads by default
  -           "--enable-pthreads --disable-w32threads")
  +           ["--enable-pthreads" "--disable-w32threads"])
          else
  -         "--disable-pthreads --disable-w32threads")
  +         ["--disable-pthreads" "--disable-w32threads"])
  +    ++ [
         (ifMinVer "0.9" "--disable-os2threads") # We don't support OS/2
         "--enable-network"
         (ifMinVer "2.4" "--enable-pixelutils")
  
positive.code: 
  let
    inherit (stdenv) isDarwin isFreeBSD isLinux isAarch32;
    inherit (stdenv.lib) optional optionals optionalString enableFeature;
  
    cmpVer = builtins.compareVersions;
    reqMin = requiredVersion: (cmpVer requiredVersion branch != 1);
  
negative.code:   ] ++ optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
        "--cross-prefix=${stdenv.cc.targetPrefix}"
        "--enable-cross-compile"
    ] ++ optional stdenv.cc.isClang "--cc=clang");
  
    nativeBuildInputs = [ addOpenGLRunpath perl pkgconfig texinfo yasm ];
  
  