emacs freezes - how to troubleshoot, build with assertions

[Jarek Czekalski]

Emacs freezes when using scroll bar with mouse. I'd like to pin it down, 
but I can't see a starting place. Tried searching info for "assert" and 
"freez", searched "configure" options for "ass". Still no idea how to 
debug it. I guess I have to build Emacs with assertions.

I am a bit frustrated when I have to ask the list because I can't find 
the starting point. Is the info hidden somewhere or absent at all? If 
this is absent, could you please put it somewhere?

Thanks,
Jarek