Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: vty-ui (user goal)
rejecting: vty-ui-1.9, 1.8, 1.7.1, 1.7, 1.6.1, 1.6, 1.5.1, 1.5, 1.4, 1.3.1,
1.3, 1.2, 1.1, 1.0.1, 1.0, 0.4 (global constraint requires ==0.3)
trying: vty-ui-0.3
trying: base-4.7.0.1/installed-e4b... (dependency of vty-ui-0.3)
next goal: mtl (dependency of vty-ui-0.3)
rejecting: mtl-2.2.1, 2.2.0.1, 2.2, 2.1.3.1, 2.1.2, 2.1.1, 2.1, 2.0.1.1,
2.0.1.0, 2.0.0.0 (conflict: vty-ui => mtl>=1.1 && <1.2)
rejecting: mtl-1.1.1.1, 1.1.1.0 (conflict: base==4.7.0.1/installed-e4b..., mtl
=> base<4.6)
rejecting: mtl-1.1.0.2, 1.1.0.1, 1.1.0.0 (conflict:
base==4.7.0.1/installed-e4b..., mtl => base<4.3)
rejecting: mtl-1.0 (conflict: vty-ui => mtl>=1.1 && <1.2)
Dependency tree exhaustively searched.