Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: Cabal (user goal)
rejecting: Cabal-1.22.4.0, 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
(global constraint requires ==1.16.0)
trying: Cabal-1.16.0
trying: base-4.8.1.0/installed-4f7... (dependency of Cabal-1.16.0)
next goal: unix (dependency of Cabal-1.16.0)
rejecting: unix-2.7.1.0/installed-643..., 2.7.1.0, 2.7.0.1, 2.7.0.0 (conflict:
Cabal => unix>=2.0 && <2.7)
rejecting: unix-2.6.0.1, 2.6.0.0 (conflict: base==4.8.1.0/installed-4f7...,
unix => base>=4.5 && <4.7)
rejecting: unix-2.5.1.1, 2.5.1.0 (conflict: base==4.8.1.0/installed-4f7...,
unix => base>=4.5 && <4.6)
rejecting: unix-2.5.0.0 (conflict: base==4.8.1.0/installed-4f7..., unix =>
base>=4.2 && <4.5)
rejecting: unix-2.4.2.0, 2.4.1.0 (conflict: base==4.8.1.0/installed-4f7...,
unix => base>=4.2 && <4.4)
rejecting: unix-2.4.0.2, 2.4.0.1 (conflict: base==4.8.1.0/installed-4f7...,
unix => base>=4.2 && <4.3)
rejecting: unix-2.4.0.0 (conflict: base==4.8.1.0/installed-4f7..., unix =>
base>=4.1 && <4.3)
rejecting: unix-2.3.2.0, 2.3.1.0, 2.3.0.0, 2.2.0.0, 2.0 (conflict:
base==4.8.1.0/installed-4f7..., unix => base<4.3)
Dependency tree exhaustively searched.