Resolving dependencies... cabal: Could not resolve dependencies: next goal: yi-contrib (user goal) rejecting: yi-contrib-0.10.1, 0.10.0, 0.8.2, 0.8.1, 0.8.0, 0.7.2, 0.7.1, 0.7.0, 0.6.7.0, 0.6.6.0, 0.6.5.0, 0.6.4.0 (global constraint requires ==0.6.3.0) trying: yi-contrib-0.6.3.0 trying: base-4.7.0.1/installed-e4b... (dependency of yi-contrib-0.6.3.0) next goal: yi (dependency of yi-contrib-0.6.3.0) rejecting: yi-0.12.0, 0.11.2, 0.11.1, 0.11.0, 0.10.1, 0.10.0, 0.8.2, 0.8.1, 0.8.0, 0.7.2, 0.7.1, 0.7.0, 0.6.7.0, 0.6.6.0, 0.6.5.0, 0.6.4.0 (conflict: yi-contrib => yi==0.6.3.0) trying: yi-0.6.3.0 next goal: unix (dependency of yi-0.6.3.0) rejecting: unix-2.7.0.1/installed-0d8... (conflict: unix => bytestring==0.10.4.0/installed-9f4..., yi => bytestring>=0.9.1 && <0.9.2) trying: unix-2.7.1.0 next goal: time (dependency of yi-0.6.3.0) rejecting: time-1.4.2/installed-bf9..., 1.5.0.1, 1.5, 1.4.2, 1.4.1, 1.4.0.2, 1.4.0.1, 1.4, 1.3 (conflict: yi => time>=1.1 && <1.3) rejecting: time-1.2.0.5, 1.2.0.4, 1.2.0.3, 1.2.0.2, 1.2.0.1, 1.2 (conflict: base==4.7.0.1/installed-e4b..., time => base>=4 && <4.7) rejecting: time-1.1.4, 1.1.3, 1.1.2.4, 1.1.2.3, 1.1.2.2, 1.1.2.1, 1.1.2.0 (conflict: unix => time>=1.2 && <1.6) rejecting: time-1.0 (conflict: yi => time>=1.1 && <1.3) Dependency tree exhaustively searched.