anchor.diff:    configureFlags = "builddir"
     + stdenv.lib.optionalString (!dllSupport) " --without-dynamic-modules"
     + stdenv.lib.optionalString (readline != null) " --with-readline"
  -  + stdenv.lib.optionalString (libffi != null) " --with-dynamic-ffi"
  -  + stdenv.lib.optionalString (libffcall != null) " --with-ffcall"
  +  # --with-dynamic-ffi can only exist with --with-ffcall - foreign.d does not compile otherwise
  +  + stdenv.lib.optionalString (ffcallAvailable && (libffi != null)) " --with-dynamic-ffi"
  +  + stdenv.lib.optionalString ffcallAvailable " --with-ffcall"
  +  + stdenv.lib.optionalString (!ffcallAvailable) " --without-ffcall"
     + stdenv.lib.concatMapStrings (x: " --with-module=" + x) withModules
     + stdenv.lib.optionalString threadSupport " --with-threads=POSIX_THREADS";
   
  
positive.code:     description = "ANSI Common Lisp Implementation";
      homepage = http://clisp.cons.org;
      maintainers = with stdenv.lib.maintainers; [raskin tohl];
      platforms = stdenv.lib.platforms.linux;
    };
  }
  
negative.code:   };
  
    inherit libsigsegv gettext coreutils;
  
    ffcallAvailable = stdenv.isLinux && (libffcall != null);
  
    buildInputs = [libsigsegv]
    ++ stdenv.lib.optional (gettext != null) gettext
    ++ stdenv.lib.optional (ncurses != null) ncurses
    ++ stdenv.lib.optional (pcre != null) pcre
    ++ stdenv.lib.optional (zlib != null) zlib
    ++ stdenv.lib.optional (readline != null) readline
    ++ stdenv.lib.optional (ffcallAvailable && (libffi != null)) libffi
    ++ stdenv.lib.optional ffcallAvailable libffcall
    ++ stdenv.lib.optionals x11Support [
      libX11 libXau libXt libXpm xproto libXext xextproto
    ];
  