anchor.diff:        extraPackages = [
           targetLlvmLibraries.compiler-rt
         ];
  -      extraBuildCommands = ''
  -        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
  -        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
  -        echo "-nostdlib++" >> $out/nix-support/cc-cflags
  -      '' + mkExtraBuildCommands cc;
  +      extraBuildCommands = mkExtraBuildCommands cc;
  +      nixSupport.cc-cflags = [
  +        "-rtlib=compiler-rt"
  +        "-B${targetLlvmLibraries.compiler-rt}/lib"
  +        "-nostdlib++"
  +      ];
       };
   
       clangNoLibc = wrapCCWith rec {
  
positive.code:       ] ++ lib.optionals (!stdenv.targetPlatform.isWasm) [
          targetLlvmLibraries.libunwind
        ];
        extraBuildCommands = ''
          echo "-rtlib=compiler-rt -Wno-unused-command-line-argument" >> $out/nix-support/cc-cflags
          echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
        '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
          echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
        '' + lib.optionalString (!stdenv.targetPlatform.isWasm && stdenv.targetPlatform.useLLVM or false) ''
          echo "-lunwind" >> $out/nix-support/cc-ldflags
        '' + lib.optionalString stdenv.targetPlatform.isWasm ''
          echo "-fno-exceptions" >> $out/nix-support/cc-cflags
        '' + mkExtraBuildCommands cc;
      };
  
      clangNoLibcxx = wrapCCWith rec {
  
negative.code:       extraPackages = [
          targetLlvmLibraries.compiler-rt
        ];
        extraBuildCommands = mkExtraBuildCommands cc;
        nixSupport.cc-cflags = [
          "-rtlib=compiler-rt"
          "-B${targetLlvmLibraries.compiler-rt}/lib"
        ];
      };
  
      clangNoCompilerRt = wrapCCWith rec {
  