[Qt-creator] Debugger hangs on breakpoint (near QSGRenderThread)

[Mateusz Loskot]

Hi,

I'm using Qt Creator 3.0.81 (Qt 5.2.0 64-bit) on Linux,
built on October 26 from the source code pulled
from the Git repository. It's debug/development build
and I'm using two separate copies of the build:
one to develop, the other to lauch and debug a plugin.

While debugging some plugins and I've noticed that
the debugging session freezes once the execution
reaches some of breakpoints. It happens fairly often,
but I haven't noticed the exact pattern of what kind of
breakpoints actually make the debugger freeze.

For example, I placed breakpoint in the CMakeProjectManager plugin's
CMakeBuildConfigurationFcatory::availaleBuilds() method, then
- the execution stops at it, then 1-5 seconds later
- the stacktrace refreshes view and displays completely unrelated,
- the step over/in/out buttons get disabled,
- the debugger is not responding on stepping,
- the only buttons that are active are pause and stop.

Here are three screenshots to show what's going on during the sequence above:
http://imageshack.com/a/img577/6858/ccqe.png
http://imageshack.com/a/img5/5714/kdn7.png
http://imageshack.com/a/img850/5031/9wvl.png

Interestingly, every time it happens, the view title bar
displays QSGRenderThread and "Running" next to it.

If I hit the blue pause button, it changes to "Stop requested"
and eventually it shows "Attempting to interrupt" which hangs forever.

The only thing I can do is to abort debugging and restart it.

I noticed similar issue while debugging other plugins like the
GenericProjectManager
and others.

I wonder, is this something known?
Do I need to tweak the Qt Creator/GDB debugger settings in some way?
Does it look like a bug and shall I report?

Best regards,
-- 
Mateusz  Loskot, http://mateusz.loskot.net