seconds_since_1970 is unsigned long, so we can't pass it as time_t or
we corrupt memory if sizeof(time_t) > sizeof(unsigned long)

--- ps/output.c
+++ ps/output.c
@@ -989,7 +989,8 @@
   const char *fmt;
   int tm_year;
   int tm_yday;
-  our_time = localtime(&seconds_since_1970);   /* not reentrant */
+  time_t sec_1970 = seconds_since_1970;
+  our_time = localtime(&sec_1970);   /* not reentrant */
   tm_year = our_time->tm_year;
   tm_yday = our_time->tm_yday;
   t = getbtime() + pp->start_time / Hertz;