Debug an obscure error on iPhone

Question

My app crashes on versions 4.2 and 4.3 of iOS. The line of code that crashes is in a C++ library:

Ais8_001_22_Circle const *circle = dynamic_cast<Ais8_001_22_Circle const*>(*sa);

The console says:

dyld: lazy symbol binding failed: can't resolve symbol ___dynamic_cast MY_APP 
because dependent dylib #2 could not be loaded

dyld: can't resolve symbol ___dynamic_cast in MY_APP 
because dependent dylib #2 could not be loaded

It would probably help if I could figure out what "dylib #2" is.

Answer 1

It turns out I needed to include the lstdc++ linker flag under iOS 4.X