Reviving an old thread...
Recall that David Pirotte had trouble linking libguile-2.0.so because
-lffi was not included in the link command, despite the fact that
`pkg-config --libs libffi' did the right thing.
I ran into the same problem trying to build guile on gNewSense/mipsel.
In my case, the problem was that I had set PKG_CONFIG=true while running
configure. I did this because it was recommended by the README in the
section on setting the BDW_GC_* variables.
Perhaps that was David's problem as well?
Mark