Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: vty (user goal)
rejecting: vty-5.2.9, 5.2.8, 5.2.7, 5.2.6, 5.2.5, 5.2.4, 5.2.3, 5.2.2, 5.2.1,
5.2.0, 5.1.4, 5.1.3, 5.1.1, 5.1.0, 5.0.2, 5.0.1, 5.0.0, 4.7.5, 4.7.4, 4.7.3,
4.7.2 (global constraint requires ==4.7.1)
trying: vty-4.7.1
next goal: Cabal (dependency of vty-4.7.1)
rejecting: Cabal-1.18.1.3/installed-715..., 1.22.3.0, 1.22.2.0, 1.22.1.1,
1.22.1.0, 1.22.0.0, 1.20.0.3, 1.20.0.2, 1.20.0.1, 1.20.0.0, 1.18.1.6,
1.18.1.5, 1.18.1.4, 1.18.1.3, 1.18.1.2, 1.18.1.1, 1.18.1, 1.18.0, 1.16.0.3,
1.16.0.2, 1.16.0.1, 1.16.0, 1.14.0, 1.12.0, 1.10.2.0, 1.10.1.0, 1.10.0.0,
1.8.0.6, 1.8.0.4, 1.8.0.2, 1.6.0.3, 1.6.0.2, 1.6.0.1, 1.4.0.2, 1.4.0.1,
1.4.0.0, 1.2.4.0, 1.2.3.0, 1.2.2.0, 1.2.1, 1.1.6 (conflict: vty =>
Cabal==1.17.*)
Dependency tree exhaustively searched.