2 Mio LOC, no problem here.

Sounds like maybe you have reverse-debugging enabled? I mean target record or target record-full?

Anyway, I seldom do step-by-step. I typically work with dprintf.

Are you talking heavily templated C++ code as well? I’ve got my suspicions about how much this affects things…

Nope, with reverse-debugging enabled it will be insanely slow, not something that you can miss.

I am curious does your project have large external dependencies or is it self-contained.