anchor.diff:  { stdenv, version, fetch, cmake, python3, llvm, libcxxabi }:
  +
  +let
  +
  +  useLLVM = stdenv.hostPlatform.useLLVM or false;
  +  bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
  +  inherit (stdenv.hostPlatform) isMusl;
  +
  +in
  +
   stdenv.mkDerivation rec {
     pname = "compiler-rt";
     inherit version;
  
positive.code:     "-DSCUDO_DEFAULT_OPTIONS=DeleteSizeMismatch=0:DeallocationTypeMismatch=0"
    ];
  
    cmakeFlags = stdenv.lib.optionals (stdenv.hostPlatform.useLLVM or false) [
      "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON"
      "-DCMAKE_C_COMPILER_TARGET=${stdenv.hostPlatform.config}"
      "-DCMAKE_ASM_COMPILER_TARGET=${stdenv.hostPlatform.config}"
      "-DCMAKE_C_FLAGS=-nodefaultlibs"
      "-DCMAKE_CXX_COMPILER_WORKS=ON"
      "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
      "-DCOMPILER_RT_BUILD_XRAY=OFF"
      "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
      "-DCOMPILER_RT_BUILD_PROFILE=OFF"
      "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
      #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
      "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
      "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
    ] ++ stdenv.lib.optionals stdenv.hostPlatform.isMusl [
      "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
      "-DCOMPILER_RT_BUILD_XRAY=OFF"
      "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
      "-DCOMPILER_RT_BUILD_PROFILE=OFF"
    ] ++ stdenv.lib.optionals (stdenv.hostPlatform.parsed.kernel.name == "none") [
      "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
      "-DCOMPILER_RT_OS_DIR=baremetal"
    ];
  
  
negative.code:   # Hack around weird upsream RPATH bug
    postInstall = stdenv.lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isWasm) ''
      ln -s "$out/lib"/*/* "$out/lib"
    '' + stdenv.lib.optionalString (useLLVM) ''
      ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbegin.o
      ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtend.o
      ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o
  