Debugging with CDB is extremely slow

Debugging of our project in Qt Creator is very slow compared to when debugging the same executable in Visual Studio. It takes minutes to hit a breakpoint or display call stack for an assert. This is not reproducible on a small sample project, where everything works well. The project I'm debugging has several milions LOC.

I've attached two outputs from debugger log. The first one is a situation when program hit a breakpoint and it took about 4 minutes to to display locals. The second one is a situation where there was an assert and it took about 5 minutes before creator displayed the file with assertion and call stack.

This is not specific to this version of Creator, the same happened for older versions.

Let me know if you need more information.