Resolving dependencies... cabal: Could not resolve dependencies: next goal: happstack (user goal) rejecting: happstack-7.0.2, happstack-7.0.1, happstack-7.0.0, happstack-6.1.8, happstack-6.1.7, happstack-6.0.6, happstack-6.0.5, happstack-6.0.4, happstack-6.0.3, happstack-6.0.2, happstack-6.0.1, happstack-6.0.0, happstack-0.5.0.3, happstack-0.5.0.2, happstack-0.5.0, happstack-0.4.1, happstack-0.3.2 (constraint from user target requires ==0.3.1) trying: happstack-0.3.1 trying: base-4.9.0.0/installed-4.9... (dependency of happstack-0.3.1) next goal: hsp (dependency of happstack-0.3.1) rejecting: hsp-0.10.0, hsp-0.9.2, hsp-0.9.1, hsp-0.9.0, hsp-0.8.0, hsp-0.7.3, hsp-0.7.2, hsp-0.7.1, hsp-0.7.0, hsp-0.6.1, hsp-0.6.0, hsp-0.5.2, hsp-0.5.1, hsp-0.5.0 (conflict: happstack => hsp>=0.4.5 && <0.5) rejecting: hsp-0.4.5 (conflict: base==4.9.0.0/installed-4.9..., hsp => base>3 && <4) rejecting: hsp-0.4.4, hsp-0.4, hsp-0.2 (conflict: happstack => hsp>=0.4.5 && <0.5) Dependency tree exhaustively searched.