Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] next goal: horde-ad (user goal)
[__0] rejecting: horde-ad-0.2.0.0 (conflict: requires unknown language
GHC2024; did you mean GHC2021?)
[__0] rejecting: horde-ad-0.1.0.0 (constraint from user target requires
==0.2.0.0)
[__0] fail (backjumping, conflict set: horde-ad)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: horde-ad