Diagnosing / debugging _dyld_start, ImageLoaderMachO::doModInitFunctions

I'm working on a substantial Mac AppKit app that has a large number of third-party libraries and frameworks, mostly C++.

I'm getting a crash on initialization of some boost::asio code that I'm fairly sure indicates different versions of boost referenced by one or more linked libs. However I can't tell from the stack trace exactly which library is causing the issue - the caller of the boost code is just ::__cxx_global_var_init.10().

I see some other forum threads about crashes in ImageLoaderMachO but they tend to focus on fixing a specific crash - I have a slightly more general question.

Are there some advanced techniques for debugging and analyzing the pre-main() work done by ImaeLoaderMachO()? I'd like to fix this crash (which I'll explore through some trial and error) but more than that I'd like to have a deterministic way to see - ideally, even breakpoint - all code that gets executed before main() to understand this app's startup/load behaviors.

Thanks for any wizardry!