Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: Workflow (user goal)
rejecting: Workflow-0.8.3, 0.8.2, 0.8.1, 0.8.0.9, 0.8.0.8, 0.8.0.7, 0.8.0.6,
0.8.0.5, 0.8.0.4, 0.8.0.3, 0.8.0.2, 0.8.0.1, 0.8.0.0, 0.7.0.7, 0.7.0.6,
0.7.0.5, 0.7.0.4, 0.7.0.3, 0.7.0.2 (global constraint requires ==0.7.0.1)
trying: Workflow-0.7.0.1
trying: base-4.8.1.0/installed-4f7... (dependency of Workflow-0.7.0.1)
trying: MonadCatchIO-mtl-0.3.1.0 (dependency of Workflow-0.7.0.1)
next goal: MonadCatchIO-transformers (dependency of MonadCatchIO-mtl-0.3.1.0)
rejecting: MonadCatchIO-transformers-0.3.1.3, 0.3.1.2, 0.3.1.1 (conflict:
MonadCatchIO-mtl => MonadCatchIO-transformers==0.3.1.0)
rejecting: MonadCatchIO-transformers-0.3.1.0 (conflict:
base==4.8.1.0/installed-4f7..., MonadCatchIO-transformers => base<4.8)
rejecting: MonadCatchIO-transformers-0.3.0.0, 0.2.2.3, 0.2.2.2, 0.2.2.1,
0.2.2.0, 0.2.1.0, 0.2.0.0, 0.1.0.1, 0.1.0.0, 0.0.2.0, 0.0.1.0 (conflict:
MonadCatchIO-mtl => MonadCatchIO-transformers==0.3.1.0)
Dependency tree exhaustively searched.