anchor.diff: -{ lib, stdenv, fetchFromGitHub, glfw, freetype, openssl, upx ? null }:
  -
  -assert stdenv.hostPlatform.isUnix -> upx != null;
  +{ lib, stdenv, fetchFromGitHub, glfw, freetype, openssl, makeWrapper, upx }:
   
   stdenv.mkDerivation rec {
     pname = "vlang";
  
positive.code:     cp -r {cmd,vlib,thirdparty} $out/lib
      mv v $out/lib
      ln -s $out/lib/v $out/bin/v
      runHook postInstall
    '';
  
  
negative.code:   propagatedBuildInputs = [ glfw freetype openssl ]
      ++ lib.optional stdenv.hostPlatform.isUnix upx;
  
    nativeBuildInputs = [ makeWrapper ];
  
    makeFlags = [
      "local=1"
      "VC=${vc}"
      # vlang seems to want to write to $HOME/.vmodules , so lets give
      # it a writable HOME
      "HOME=$TMPDIR"
    ];
  
    installPhase = ''
      runHook preInstall
  