Feel free to open issue reports if (the most recent version of) ocamldebug is not behaving correctly.
Note that there is a chronic lack of people interested in helping maintain and improve ocamldebug; the Coq people are heavy users of it, and they have bugreports and feature requests, but we currently lack the manpower to address some of them. If someone around is an ocamldebug user, and would be willing to invest some effort into looking at the codebase and contributing to it (for example, there is a patchset from whitequark that implements debugging of dynlinked code, but I haven’t been able to find a motivated reviewer yet), that could be very helpful.