anchor.diff:        echo $cc $binutils $libc > $out/nix-support/propagated-user-env-packages
   
         echo ${toString extraPackages} > $out/nix-support/propagated-native-build-inputs
  -    ''
  -
  -    + optionalString (stdenv.isSunOS && nativePrefix != "") ''
  -      # Solaris needs an additional ld wrapper.
  -      ldPath="${nativePrefix}/bin"
  -      exec="$ldPath/ld"
  -      wrap ld-solaris ${./ld-solaris-wrapper.sh}
       '')
   
       + ''
  
positive.code:     ''
  
      + (if nativeTools then ''
        ccPath="${if stdenv.isDarwin then cc else nativePrefix}/bin"
        ldPath="${nativePrefix}/bin"
      '' else ''
        echo $cc > $out/nix-support/orig-cc
  
negative.code:       # explicit overrides of the dynamic linker by callers to gcc/ld
        # (the *last* value counts, so ours should come first).
        echo "-dynamic-linker" $dynamicLinker > $out/nix-support/libc-ldflags-before
      '')
  
      + optionalString (!nativeLibc) ''
  