Resolving dependencies... cabal: Could not resolve dependencies: next goal: progression (user goal) rejecting: progression-0.5.0.2, 0.5.0.1, 0.5 (global constraint requires ==0.4) trying: progression-0.4 trying: base-4.8.1.0/installed-4f7... (dependency of progression-0.4) next goal: haskeline (dependency of progression-0.4) rejecting: haskeline-0.7.2.1/installed-0a4..., 0.7.2.1, 0.7.2.0, 0.7.1.3, 0.7.1.2, 0.7.1.1, 0.7.1.0, 0.7.0.3, 0.7.0.2, 0.7.0.1, 0.7.0.0 (conflict: progression => haskeline>=0.6 && <0.7) trying: haskeline-0.6.4.7 next goal: unix (dependency of haskeline-0.6.4.7) rejecting: unix-2.7.1.0/installed-643..., 2.7.1.0, 2.7.0.1, 2.7.0.0, 2.6.0.1, 2.6.0.0 (conflict: haskeline => unix>=2.0 && <2.6) 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.