= werrstr: set the system error string     include "sys.m";    sys := load Sys Sys->PATH;     werrstr(s: string): int; When  a  system  call fails, it returns an error value (often-1) and records a string  describing  the  error  in  a  per-process  location.   The  verb  r in sys-print(2) outputs theerror string.  Werrstr sets the process's error string to  s,to  allow a function in a module to mimic the error reportinginterface of a system call. == see ALSOsys-intro(2), sys-print(2)