Re: how to debug a program when the session freezes

[Andrew Sobala <aes gnome org>]

Elijah Newren wrote:

> On 1/9/06, Andrew Sobala <aes gnome org> wrote:
>  
>
> > Rod Butcher wrote:
> >
> >    
> >
> > > Can somebody tell me how to get a gdb trace when the app I'm debugging
> > > freezes my X session ? I'm running gnome-system-monitor from a
> > > terminal : gdb gnome-system-monitor which freezes up the X session when
> > > I click on the top menu line. The only way I can get out is by by
> > > al-ctl-f1 and killing the X session from the linux command line. How do
> > > I send the gdb output to a file for later retrieval, and is it possible
> > > to get the stack trace some other way, without X ?
> > > thanks
> > >
> > >
> > >      
> > You can control-alt-F1 first, export DISPLAY=:0, then run gdb from
> > there. The app should appear in your X session, but gdb will run in the
> > terminal.
> >    
>
> Well, you might have access to the Xserver denied depending on your
> distro's setup and handling of X, so this wouldn't work for everyone
> without more effort.
Yes, this is assuming you're not using a distro with an annoying 
security setup ;-)

In the times that I've had access problems with X, running "xhost +" 
(which doesn't require root access on Ubuntu) has fixed it. That allows 
access to the X server by everyone; man xhost tells you what the finer 
grained controls are.

However, there may be situations where this doesn't work. I know 
virtually nothing about X security.

--
Andrew