Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: intero (user goal)
rejecting: intero-0.1.19, intero-0.1.18 (constraint from user target requires
==0.1.17)
trying: intero-0.1.17
next goal: ghc (dependency of intero-0.1.17)
rejecting: ghc-8.0.1.20161018/installed-8.0... (conflict: intero => ghc>=7.8
&& <=8.0.1)
Dependency tree exhaustively searched.