anchor.diff:        "-Uinstallusrbinperl"
         "-Dinstallstyle=lib/perl5"
         "-Duseshrplib"
  -      "-Dlocincpth=${libc.dev or libc}/include"
  -      "-Dloclibpth=${libc.out or libc}/lib"
  +      "-Dlocincpth=${libcInc}/include"
  +      "-Dloclibpth=${libcLib}/lib"
       ]
       ++ optional enableThreading "-Dusethreads";
   
  
positive.code:     unset LD_LIBRARY_PATH
    '';
  
    postInstall =
      ''
        # Remove dependency between "out" and "man" outputs.
        rm $out/lib/perl5/*/*/.packlist
  
        # Remove dependencies on glibc.dev and coreutils.
        substituteInPlace $out/lib/perl5/*/*/Config_heavy.pl \
          --replace ${stdenv.glibc.dev or "/blabla"} /no-such-path \
          --replace $man /no-such-path
      ''; # */
  
    meta = {
  
negative.code: 
    enableParallelBuilding = true;
  
    preConfigure = ''
        configureFlags="$configureFlags -Dprefix=$out -Dman1dir=$out/share/man/man1 -Dman3dir=$out/share/man/man3"
      '' + optionalString stdenv.isArm ''
        configureFlagsArray=(-Dldflags="-lm -lrt")
      '' + optionalString stdenv.isDarwin ''
        substituteInPlace hints/darwin.sh --replace "env MACOSX_DEPLOYMENT_TARGET=10.3" ""
      '' + optionalString (!enableThreading) ''
  