- `main_loop()' and `main()', then something's wrong: are you sure
- the core file came from that program?
+ `main_loop()' and `main()', then something went wrong, and the
+ core file is bogus. If the lines it prints out contain only
+ question marks, then the core file is bogus. Are you sure the
+ core file came from that program? Did you compile with -g, as
+ explained above? If you don't compile with -g, the core file
+ won't have any information in it.
+
+ Never ever ever mail me (or anyone) a core file. They are huge,
+ and are only meaningful on the machine that generated them, with
+ the exact executable that generated them, neither of which anyone
+ but you has access to. Don't mail me a core file unless you're
+ also planning on mailing me your computer.