vlang: eliminate env.VFLAGS

  nativeBuildInputs = [ makeWrapper ];

  buildInputs = lib.optional stdenv.isDarwin darwin.apple_sdk.frameworks.Cocoa;

  buildInputs = [

    binaryen

  ] ++ lib.optionals stdenv.isDarwin [

    darwin.apple_sdk.frameworks.Cocoa

  ] ++ lib.optionals stdenv.isLinux [

    xorg.libX11

    xorg.libXau

    xorg.libXdmcp

    xorg.xorgproto

  ];

  makeFlags = [

    "local=1"

  ];

  env.VC = vc;

  env.VFLAGS = toString ([

    "-cc ${stdenv.cc}/bin/cc"

    "-no-retry-compilation"

    "-ldflags -L${binaryen}/lib"

  ]

  # builder error: Header file <X11/Xlib.h>, needed for module `clipboard.x11` was not found.

  ++ lib.optionals stdenv.isLinux [

    "-cflags -I${xorg.libX11.dev}/include"

    "-cflags -I${xorg.xorgproto}/include"

    "-ldflags -L${xorg.libX11}/lib"

    "-ldflags -L${xorg.libxcb}/lib"

    "-ldflags -lxcb"

    "-ldflags -L${xorg.libXau}/lib"

    "-ldflags -lXau"

    "-ldflags -L${xorg.libXdmcp}/lib"

    "-ldflags -lXdmcp"

  ]);

  preBuild = ''

    export HOME=$(mktemp -d)

  # vcreate_test.v requires git, so we must remove it when building the tools.

  preInstall = ''

    mv cmd/tools/vcreate/vcreate_test.v $HOME/vcreate_test.v

  ''

  # builder error: Header file <Cocoa/Cocoa.h>, needed for module `clipboard` was not found.

  + lib.optionalString stdenv.isDarwin ''

    for flag in $NIX_CFLAGS_COMPILE; do

      if [[ $flag == /*/Library/Frameworks ]]; then

        VFLAGS+=" -ldflags -F$flag"

      fi

    done

  '';

  installPhase = ''