On OS X, there is no dylib, so no GHCi. You can create these by hand:

In the BDD library distribution's mem/
gcc -arch i386 -I<include path> -L<library path> -O *.c -shared -fPIC -o libmem.dylib
(copy libmem.dylib into a library directory)

In the BDD library distribution's bddlib/
gcc -arch i386 -I<include path> -L<library path> -lmem -O *.c -shared -fPIC -o libbdd.dylib
(copy libbdd.dylib into a library directory)