Edit: oh.. and the amiga library system isn't immune to some of these problems, I keep two slightly incompatible versions of bgui.library handy, since I have two apps that work with one but not the other, and I can't run both at the same time.
Yep, that's true. This is why I have a manually patched "agui.library" (and the corresponding application) and the newer bgui.library here. BTW: I you scan through your SOBJS: you might find some .so's that actually have a proper Amiga version string, which makes it easier for us as users. So it CAN be done - but is not usual at the moment. I guess this is one of the shortcomings that we do not have a proper and updated RKRM/style guide and coding rules.