Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: happs-tutorial (user goal)
rejecting: happs-tutorial-0.9.5, 0.9.4, 0.9.3, 0.9.2, 0.9.1, 0.9.0, 0.8.1
(global constraint requires ==0.8)
trying: happs-tutorial-0.8
trying: base-4.8.1.0/installed-4f7... (dependency of happs-tutorial-0.8)
trying: happstack-helpers-0.56 (dependency of happs-tutorial-0.8)
next goal: happstack-ixset (dependency of happstack-helpers-0.56)
rejecting: happstack-ixset-6.0.1, 6.0.0 (conflict: happstack-helpers =>
happstack-ixset>=0.3 && <0.6)
trying: happstack-ixset-0.5.0.3
next goal: happstack-util (dependency of happstack-ixset-0.5.0.3)
rejecting: happstack-util-6.0.3, 6.0.2, 6.0.0 (conflict: happstack-ixset =>
happstack-util>=0.5 && <0.6)
trying: happstack-util-0.5.0.3
next goal: strict-concurrency (dependency of happstack-util-0.5.0.3)
rejecting: strict-concurrency-0.2.4.1, 0.2.4 (conflict:
base==4.8.1.0/installed-4f7..., strict-concurrency => base>=4 && <4.6)
rejecting: strict-concurrency-0.2.3 (conflict: base==4.8.1.0/installed-4f7...,
strict-concurrency => base>=3 && <4.3)
rejecting: strict-concurrency-0.2.2, 0.2.1 (conflict:
base==4.8.1.0/installed-4f7..., strict-concurrency => base>=3 && <4)
rejecting: strict-concurrency-0.2, 0.1 (conflict:
base==4.8.1.0/installed-4f7..., strict-concurrency => base<4.3)
Backjump limit reached (change with --max-backjumps).