Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: c2hs (user goal)
rejecting: c2hs-0.28.1, c2hs-0.27.1, c2hs-0.26.2, c2hs-0.26.1, c2hs-0.25.2,
c2hs-0.25.1, c2hs-0.24.1, c2hs-0.23.1, c2hs-0.22.1, c2hs-0.21.1, c2hs-0.20.1,
c2hs-0.19.1, c2hs-0.18.2, c2hs-0.18.1, c2hs-0.17.2, c2hs-0.17.1, c2hs-0.16.6
(constraint from user target requires ==0.16.5)
trying: c2hs-0.16.5
next goal: base (dependency of c2hs-0.16.5)
rejecting: base-4.9.0.0/installed-4.9... (conflict: c2hs => base>=2 && <4.8)
rejecting: base-4.9.0.0, base-4.8.2.0, base-4.8.1.0, base-4.8.0.0,
base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1, base-4.6.0.0,
base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0, base-4.3.1.0,
base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0, base-4.1.0.0,
base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from non-upgradeable
package requires installed instance)
Dependency tree exhaustively searched.