anchor.diff:  , langAda ? false
   , langObjC ? stdenv.targetPlatform.isDarwin
   , langObjCpp ? stdenv.targetPlatform.isDarwin
  +, langD ? false
   , langGo ? false
   , reproducibleBuild ? true
   , profiledCompiler ? false
  
positive.code:         url = "https://github.com/fxcoudert/gcc/compare/releases/gcc-11.1.0...gcc-11.1.0-arm-20210504.diff";
          sha256 = "sha256-JqCGJAfbOxSmkNyq49aFHteK/RFsCSLQrL9mzUCnaD0=";
        })
  
        # Obtain latest patch with ../update-mcfgthread-patches.sh
        ++ optional (!crossStageStatic && targetPlatform.isMinGW) ./Added-mcf-thread-model-support-from-mcfgthread.patch;
  
negative.code: assert langGo -> langCC;
  assert langAda -> gnatboot != null;
  
  # TODO: fixup D bootstapping, probably by using gdc11 (and maybe other changes).
  #   error: GDC is required to build d
  assert !langD;
  
  # threadsCross is just for MinGW
  assert threadsCross != null -> stdenv.targetPlatform.isWindows;
  
  