QT Creator 3.0.1 Debugging On Windows Suddenly Becomes Slow. Why?

Question

I've been using QT Creator 3.0.1 on Windows fine for a long time and now, all of a sudden, debugging is incredibly slow. Stepping over, seeing locals in the watch window, resuming execution, everything takes many minutes to work. If I hit a breakpoint or crash and try to step over, I see the message "Run requested..." and then nothing for a long time. The normal debugging UI is disabled (pause, stop, etc) but the stop button in the Application Output window is enabled and works.

Details on my setup:

• Running on Windows XP SP3 32bit
• Using kit Desktop 5.2.1 MSVC2010 32bit
• cdb.exe from Debugging Tools for Windows x86
• using the default symbol cache location and server that QT Creator gives me.

I've deleted and recreated the symbol cache, repaired the Debugging Tools for Windows install but nothing changed.

What could be causing this? Are there files or folders that need to be cleaned, cleared, reset?

Answer 1

Turns out the problem was with the watch window. I had two variables I had entered manually in the watch window. For some reason, having them totally kills the debugger performance.

Simply removing them from the watch window didn't seem to work, though. I had to manually remove them from the default.qws file. The file is located in c:\Documents and Settings\\Application Data\QtProject\qtcreator\default.qws.

I found a node "value-Watchers" containing my two variables and removed the whole Data section that contained them. After that, debugging performance was back to normal.