Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: hermit (user goal)
rejecting: hermit-1.0.0.0, 0.7.1.0, 0.7.0.0, 0.6.0.0, 0.5.0.0, 0.4.0.0,
0.3.2.0, 0.3.1.0, 0.3.0.0, 0.2.0.0, 0.1.8.0 (global constraint requires
==0.1.6.0)
trying: hermit-0.1.6.0
next goal: ghc (dependency of hermit-0.1.6.0)
rejecting: ghc-7.10.2/installed-a64... (conflict: hermit => ghc==7.6.*)
Dependency tree exhaustively searched.