If you’re using DragonFly 3.5, your next update should be a full buildworld.  That’s because John Marino is adding the framework for symbol versioning.  This means that individual library (.so) files will internally keep track of newer and older symbols.  The current behavior is to name the files differently, which can cause problems if an expected, linked file is missing – even if the needed symbols are present.  The basic framework is being added now, and will be turned on all at once, to minimize the number of times that full buildworld is needed.