anchor.diff: -{ stdenv, fetchurl, zlib ? null, zlibSupport ? true, bzip2, includeModules ? false
  -, sqlite, tcl, tk, x11, openssl, readline, db, ncurses, gdbm, libX11, self, callPackage }:
  +{ stdenv, fetchurl, self, callPackage
  +, bzip2, openssl
  +
  +, includeModules ? false
  +
  +, db, gdbm, ncurses, sqlite, readline
  +
  +, tcl ? null, tk ? null, x11 ? null, libX11 ? null, x11Support ? true
  +, zlib ? null, zlibSupport ? true
  +}:
   
   assert zlibSupport -> zlib != null;
  +assert x11Support -> tcl != null
  +                  && tk != null
  +                  && x11 != null
  +                  && libX11 != null;
   
   with stdenv.lib;
   
  
positive.code:       # if DETERMINISTIC_BUILD env var is set
        ./deterministic-build.patch
      ];
      
    preConfigure = ''
        # Purity.
        for i in /usr /sw /opt /pkg; do
  
negative.code: 
    buildInputs =
      optional (stdenv ? cc && stdenv.cc.libc != null) stdenv.cc.libc ++
      [ bzip2 openssl ]
      ++ optionals includeModules (
          [ db gdbm ncurses sqlite readline
          ] ++ optionals x11Support [ tcl tk x11 libX11 ]
      )
      ++ optional zlibSupport zlib;
  
    # Build the basic Python interpreter without modules that have
  