Do not use C<getopt> or C<getopt_long> in *C<_r> (directly or
indirectly)
-C<getopt> uses global variables and behaves badly in a multithreaded
+C<getopt> uses global variables and behaves badly in a multi-threaded
application when called concurrently. Instead provide a *_r function
taking all options as function parameters. You may provide argc and
**argv arguments for variable length argument lists. See