Strange gdb behavior when debugging Qt apps

Strange gdb behavior when debugging Qt apps

[Αλέξανδρος Καρυπίδης (Alexandros Karypidis)]

Hello everyone,

I am facing a rather strange problem using gdb.  I have written a simple Qt 
application which creates a window with a few menu choices.  When I run the 
application (no debugging), everything is ok.  If I try to run it within gdb 
however, the fonts used are unreadable.  They letters are very small and one 
cannot distinguish them.  Does anyone have any clue regading this strange 
behavior?

Thanks,
Alexandros

Re: Strange gdb behavior when debugging Qt apps

[Kevin Buettner]

On Feb 4,  4:46pm, =?iso-8859-7?b?wevd7uHt5PHv8iDK4fH18N/k5/I=?= (Ale wrote:

> I am facing a rather strange problem using gdb.  I have written a simple Qt 
> application which creates a window with a few menu choices.  When I run the 
> application (no debugging), everything is ok.  If I try to run it within gdb 
> however, the fonts used are unreadable.  They letters are very small and one 
> cannot distinguish them.  Does anyone have any clue regading this strange 
> behavior?

In the course of starting up the process to be debugged, gdb invokes
the shell.  Could it be that a .bashrc, .cshrc, or the like is setting
(or unsetting) an environment variable which is influencing the font
size?

Kevin

Re: Strange gdb behavior when debugging Qt apps

[Αλέξανδρος Καρυπίδης (Alexandros Karypidis)]

So far noone has mentioned anything in the Qt mailing list.  Moreover, I 
tried running gdb against standard qt apps (like qtcups) and the fonts were 
ok, so it's probably not the environment.

Furthermore, it seems that this is thread-related, because it occurs only 
with applications spawning other threads.  For example, I ran gdb with qtella 
(a Qt gnutella client which spawns threads\b) and had the same "garbled fonts" 
problem.

More specifically, when gdb's output contains somethin like:

"[New Thread XXXX (LWP YYYYY)]"

Then, the fonts are garbled...

> > I am facing a rather strange problem using gdb.  I have written a simple
> > Qt application which creates a window with a few menu choices.  When I
> > run the application (no debugging), everything is ok.  If I try to run it
> > within gdb however, the fonts used are unreadable.  They letters are very
> > small and one cannot distinguish them.  Does anyone have any clue
> > regading this strange behavior?
>
> In the course of starting up the process to be debugged, gdb invokes
> the shell.  Could it be that a .bashrc, .cshrc, or the like is setting
> (or unsetting) an environment variable which is influencing the font
> size?