bt:make-thread uses a funny table with custom bindings to initialize standardized globals like *print-readably*.
This seriously interferes with applications using Hunchentoot.
I have already posted to bordeaux-thread-devel stating that the new thread should probably inherit the values from the parent thread, but things are slow there I think.
FYI we now have this in Weblocks to work around at least the aforementioned variable (which causes the biggest problem because a lot of ~S format directives suddenly become trip mines):
(defmethod process-connection ((acceptor weblocks-acceptor) socket) (let ((*print-readably* nil)) (call-next-method)))
Hunchentoot should probably provide a similar workaround until the thing is sorted out on the BT side.
Other rebindings seem to be pretty harmless in comparison, but YMMV. :(
Leslie