[mythtv] howto? gdb trace

[Jim Westfall]

Stuart Auchterlonie <stuarta at squashedfrog.net> wrote [02.06.06]:
> 
> That as documented is for starting up the program under gdb.
> 
> My instructions are for the alternative way which is to ATTACH
> gdb to a RUNNING program. Once you attach gdb you have to 
> tell the program to continue by issuing 'cont' and then wait
> for it to segfault.
> 

I make use of core files when trying to debug crashes.

ulimit -c unlimited
export DISPLAY=:0
while [ 1 ];do /usr/local/bin/mythfrontend -v all;sleep 1;done 

when mythfrontend crashes it will create core.<pid>, which you can then 
use with gdb -c core.<pid> /usr/local/bin/mythfrontend to examine the 
backtrace.  same deal with backend or commflag crashes.

The core files allow you to get multiple data points for a re-occurring 
crash and then compare data within the backtraces.

If you use this method just need to make sure to delete the core files 
whenever you update mythtv or libs since it will invalidate the data in 
them.  

jim