anchor.diff:  
     # Explicitly link against libgcc_s, to work around the infamous
     # "libgcc_s.so.1 must be installed for pthread_cancel to work".
  -  LDFLAGS = "-lgcc_s";
  +
  +  # don't have "libgcc_s.so.1" on darwin
  +  LDFLAGS = stdenv.lib.optionalString (!stdenv.isDarwin) "-lgcc_s";
   
     postInstall = ''
       wrapProgram $out/bin/guile-snarf --prefix PATH : "${gawk}/bin"
  
positive.code:             s|-lltdl|-L${libtool}/lib -lltdl|g'
    '';
  
    doCheck = true;
  
    setupHook = ./setup-hook-2.0.sh;
  
  
negative.code:       linking, a foreign function call interface, and powerful string
        processing.
      '';
    };
  }
  
  