Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: threepenny-gui (user goal)
rejecting: threepenny-gui-0.6.0.4, 0.6.0.3, 0.6.0.2, 0.6.0.1, 0.5.0.0,
0.4.2.0, 0.4.1.0, 0.4.0.2, 0.4.0.1, 0.4.0.0, 0.3.0.1, 0.3.0.0, 0.2.0.1,
0.2.0.0, 0.1.0.1 (global constraint requires ==0.1.0.0)
trying: threepenny-gui-0.1.0.0
trying: base-4.8.1.0/installed-4f7... (dependency of threepenny-gui-0.1.0.0)
next goal: json (dependency of threepenny-gui-0.1.0.0)
rejecting: json-0.9.1, 0.9, 0.8, 0.7, 0.6 (conflict: threepenny-gui =>
json>=0.4.4 && <0.6)
trying: json-0.5
trying: json-0.5:+generic
trying: json-0.5:-mapdict
trying: json-0.5:+parsec
trying: json-0.5:+pretty
rejecting: json-0.5:+split-base (conflict: base==4.8.1.0/installed-4f7...,
json-0.5:split-base => base>=4 && <4.8)
rejecting: json-0.5:-split-base (conflict: base==4.8.1.0/installed-4f7...,
json-0.5:split-base => base<3)
Dependency tree exhaustively searched.