gdb continues when I want "next"

[Markus.Grunwald@pruftechnik.com]

Hello,

Using gdb 6.3 (where the version doesn't matter that much. I had the same 
trouble with 6.6) on an up to date debian etch I have (at least) two 
errors:

1) I set (exactly) one breakpoint. gdb stops on it. But more often then 
not when you issue a "next" or "finish" command, the program just 
continues without halt and breaks at this breakpoint agin. The program 
that is debugged is multi threaded.
I _suspect_ that this only happens the first time that I debug the 
program: When the program ends and I type "run" for the second (and more) 
time, I can degub quite fine.


2) Conditions as above, but: Sometimes, I get this when reaching the 
breakpoint for the first time:

Breakpoint 1, CPTLinearGraphic::CalculateLinLines (this=0x9251de0)
    at 
/home/gru/projects/vxp/branches/branch-0-2-10-X/Dafit_Code/drawdevices/CPTLinearGraphic.cpp:1640
(gdb) n
(gdb) n
Detaching after fork from child process 29873.
[Thread -1863816272 (LWP 29869) exited]

Program received signal SIGTRAP, Trace/breakpoint trap.
[Switching to Thread -1863816272 (LWP 29869)]
0xb7446891 in __nptl_death_event () from 
/lib/tls/i686/cmov/libpthread.so.0
(gdb) fin
Run till exit from #0  0xb7446891 in __nptl_death_event ()
   from /lib/tls/i686/cmov/libpthread.so.0
0x90e86490 in ?? ()
(gdb) 
Run till exit from #0  0x90e86490 in ?? ()
Warning:
Cannot insert breakpoint 0.
Error accessing memory address 0x0: Input/output error.


I really need some help, since my colleagues are starting to kill me 
because thay can't debug...
One more note: The debugged program is compiled with gcc 2.95.4. Ancient, 
but we have no other choice at the moment... :(


P.S. Sorry to Daniel, I should have postet this to the list the first time 
...

Best regards

Markus Grunwald
Softwareentwicklung

PRÜFTECHNIK Condition Monitoring GmbH
Oskar-Messter-Straße 19-21
85737 Ismaning
www.pruftechnik.com
Tel: +49 (0)89 99616177
Fax: +49 (0)89 99616200

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