Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: llvm-ffi (user goal)
rejecting: llvm-ffi-3.0.0.1 (conflict: requires pkg-config package llvm==3.0,
not found in the pkg-config database)
rejecting: llvm-ffi-3.0.0 (constraint from user target requires ==3.0.0.1)
Dependency tree exhaustively searched.