The only other thing I can think of to suggest is to inspect the result of
(asdf:find-system :laturk-unique)
with particular attention to the component-pathname slot (I don't have the code in front of me, I'm afraid; this slot name may be wrong, but it should be easy to figure out the right one in the inspector).
Another thing to try:
collect the result of
(asdf::traverse (make-instance 'asdf:load-op) (asdf:find-system :laturk-unique))
I think it might be helpful to take that (let's say its bound to PLAN) and do:
(mapcar #'asdf::component-pathname (mapcar #'second plan))
which should give you the component pathnames of every component in the load plan asdf builds.
I'm hoping this will clarify matters.
best, r