- * If it gets an X error, where did it come from? Run the
- program under a debugger; set a breakpoint on `exit';
- start the program with the `-sync' command-line option;
- and show me the stack trace when it stops.
+ To extract a stack trace from a core file with dbx, do this:
+
+ dbx ./the-program ./core
+ where
+
+ If the bottom few lines of the output don't include the functions
+ `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.
+
+ * If it gets an X error, where did it come from? Run
+ xscreensaver with the `-sync' command-line option. When `-sync'
+ is used, X errors will cause xscreensaver to dump a core file.
+ Look at the core file with a debugger and show me the stack trace,
+ as above: I need to know where in xscreensaver that X error came
+ from.