@deftypefn Extension void pex_free (struct pex_obj @var{obj})
-Clean up and free all data associated with @var{obj}.
+Clean up and free all data associated with @var{obj}. If you have not
+yet called @code{pex_get_times} or @code{pex_get_status}, this will
+try to kill the subprocesses.
@end deftypefn