anchor.diff:        libcxx = null;
         bintools = bintoolsNoLibc';
         extraPackages = [ ];
  -      extraBuildCommands = ''
  -        echo "-nostartfiles" >> $out/nix-support/cc-cflags
  -      '' + mkExtraBuildCommands0 cc;
  +      extraBuildCommands = mkExtraBuildCommands0 cc;
  +      nixSupport.cc-cflags = [ "-nostartfiles" ];
       };
   
       clangNoCompilerRtWithLibc = wrapCCWith rec {
  
positive.code:       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
        '' + mkExtraBuildCommands cc;
      };
  
      clangNoCompilerRt = wrapCCWith rec {
  
negative.code:       ] ++ lib.optionals (!stdenv.targetPlatform.isWasm) [
          targetLlvmLibraries.libunwind
        ];
        extraBuildCommands = mkExtraBuildCommands cc;
        nixSupport.cc-cflags =
          [ "-rtlib=compiler-rt"
            "-Wno-unused-command-line-argument"
            "-B${targetLlvmLibraries.compiler-rt}/lib"
          ]
          ++ lib.optional (!stdenv.targetPlatform.isWasm) "--unwindlib=libunwind"
          ++ lib.optional
            (!stdenv.targetPlatform.isWasm && stdenv.targetPlatform.useLLVM or false)
            "-lunwind"
          ++ lib.optional stdenv.targetPlatform.isWasm "-fno-exceptions";
      };
  
      clangNoLibcxx = wrapCCWith rec {
  