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You have two choices.

I will explain these in detail as I do not know your level of experience using debug techniques and for the benefit of other newbies.

1) On the projects folder, select the debug mode in the "Build Configuration for" project dropdown.
Go to the debug tab so you can run in debug mode and click the debug button. Allow the debug to run until it stops due to the SEG fault. This may take some time depending on your processor and the amount of memory you have, but expect quite a few seconds from the time the error pops up and the backtrace fills the debug window. The trace listed is in the reverse order the code lines were called. Look for the last line of code in your code that is reference. This is the offending line. The lines above it are the called methods in other modules that may or may not work. It may be obvious from the listing what is going wrong in your code or linkage (missing libs, etc.).

2) On the projects folder, select the debug mode in the "Build Configuration for" project dropdown. Build the project.
Open a terminal window that has the Qt SDK environment variables defined properly. Change to the debug folder of your application and execute the debugger for your executable (e.g. gdb ./myapp.exe). The debugger will open and wait for your instructions. Enter "r" to run the debugger against your executable. Wait for the error window to pop up and for gdb to display the line that it stopped on along with any error message that may be issued. In gdb enter "where" to give you a traceback list of where your app errored. It should look very similar to the listing in QtCreator debug mode with some slight differences depending on OS and debugger.

In both scenarios the debugger will give you the error backtrace to allow you to debug the problem. Often segmentation faults are due to calling on a defined but un-instantiated object. The backtrace list should point to which object that may be.

I had the same problem . All I did was run the program in debug mode as stated by ad5xj ( without setting breakpoint or starting console) and then the line at which I received the error the debugger stopped.I realized that there was a redundant variable there that I was not using . Commented the variable and blamo ... the program runs in debug mode as well.

First of all, my environment:

Quoted

Ubuntu 12.04
C++ gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)
Qt Creator 2.4.1 Based on Qt 4.8.0 (32 bit) Built on Mar 21 2012 at 23:05:03
Eclipse IDE for C/C++ Linux Developers Version: Indigo Service Release 2 Build id: 20120216-1857

I've got exactly the same problem now. I've got no idea why it is so.
I tried both Eclipse and QtCreator. Under Eclipse, my application runs fine, but under QtCreator, the application always meeting the SIGSEGV error:

Quoted

The inferior stopped because it received a signal from the Operating System.

Signal name :
SIGSEGV
Signal meaning :
Segmentation fault

Why the same code passed one IDE, but failed the other????weird...


Cheers
Pei

different compiler?

either way, it means that there is something wrong with you program - most likely it is something that is 'undefined behaviour', and you are just getting lucky with one compiler/ide

Hi, Amleto, Thank you very much for your prompt reply ! Thank you !!

However,
1) I don't think it has something to do with the compilers.
I built 11 libraries under Eclipse, and 7 applications under QtCreator, which are based on those 11 libraries. 6 out of these 7 applications work perfect under QtCreator, and there is only 1 doesn't work properly.

Since 6 are working. Thus, I don't think there is a problem with the compiler. In fact, both Eclipse and QtCreator are using the compiler GCC.

2) I don't think there are some problems with my code as well.
Because my code work fine under Codelite (this one supports qmake well) and Visual Studio 2010 (with Qt Integrator).

Conclusion: It could be a problem about the settings of compiler? I've no idea.


Anyway, thank you for your reply.


Best regards
Pei

Quoted from "Amleto"

either way, it means that there is something wrong with you program - most likely it is something that is 'undefined behaviour', and you are just getting lucky with one compiler/ide

pick a thread you want replies in please, I am not goign to keep looking at this thread on both forums.