I don't doubt the Bullet source code is "correct". I meant I should check if the call in question is surrounded by #ifdefs or something similar which would explain why that one symbol is missing, maybe I am compiling it wrong. I am quite sure my building or linking to Bullet is to blame here...
I should also add that I have almost no first-hand experience building for anything other than Windows. Anyway, this will have to wait until my current task is done.