Resolving dependencies... cabal: Could not resolve dependencies: next goal: happstack-server (user goal) rejecting: happstack-server-7.4.6.2, happstack-server-7.4.6.1, happstack-server-7.4.6, happstack-server-7.4.5, happstack-server-7.4.4, happstack-server-7.4.3, happstack-server-7.4.2, happstack-server-7.4.1, happstack-server-7.4.0, happstack-server-7.3.9, happstack-server-7.3.8, happstack-server-7.3.7, happstack-server-7.3.6, happstack-server-7.3.5, happstack-server-7.3.4, happstack-server-7.3.3, happstack-server-7.3.2, happstack-server-7.3.1, happstack-server-7.3.0, happstack-server-7.1.7.1, happstack-server-7.1.7, happstack-server-7.1.6, happstack-server-7.1.5, happstack-server-7.1.4, happstack-server-7.1.3, happstack-server-7.1.2, happstack-server-7.1.1, happstack-server-7.1.0, happstack-server-7.0.7, happstack-server-7.0.6, happstack-server-7.0.5, happstack-server-7.0.4, happstack-server-7.0.3, happstack-server-7.0.2, happstack-server-7.0.1, happstack-server-7.0.0, happstack-server-6.6.5, happstack-server-6.6.4, happstack-server-6.6.3, happstack-server-6.6.2, happstack-server-6.5.7, happstack-server-6.5.6, happstack-server-6.5.4, happstack-server-6.5.3, happstack-server-6.5.2, happstack-server-6.5.1, happstack-server-6.4.6, happstack-server-6.4.5, happstack-server-6.4.4, happstack-server-6.4.3, happstack-server-6.4.2, happstack-server-6.4.1, happstack-server-6.3.1, happstack-server-6.2.5, happstack-server-6.2.4, happstack-server-6.2.3, happstack-server-6.2.2, happstack-server-6.2.1, happstack-server-6.1.6, happstack-server-6.1.5, happstack-server-6.1.4, happstack-server-6.1.3, happstack-server-6.1.2, happstack-server-6.1.0, happstack-server-6.0.3, happstack-server-6.0.2, happstack-server-6.0.1, happstack-server-6.0.0, happstack-server-0.5.0.4, happstack-server-0.5.0.3, happstack-server-0.5.0.2 (constraint from user target requires ==0.5.0) trying: happstack-server-0.5.0 trying: base-4.9.0.0/installed-4.9... (dependency of happstack-server-0.5.0) next goal: MaybeT (dependency of happstack-server-0.5.0) rejecting: MaybeT-0.1.2, MaybeT-0.1.1 (conflict: base==4.9.0.0/installed-4.9..., MaybeT => base<4.8) rejecting: MaybeT-0.1.0 (conflict: base==4.9.0.0/installed-4.9..., MaybeT => base<4.3) Dependency tree exhaustively searched.