Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] next goal: opus (user goal)
[__0] rejecting: opus-0.3.0.0 (conflict: pkg-config package opus-any, not
found in the pkg-config database)
[__0] fail (backjumping, conflict set: opus)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: opus