Resolving dependencies... cabal: Could not resolve dependencies: next goal: GPipe (user goal) rejecting: GPipe-2.1.5, 1.4.1, 2.1.4, 2.1.3, 2.1.2, 2.1.1, 2.1, 2.0.2, 2.0.1, 2.0, 1.4, 1.3.2, 1.3.1, 1.3, 1.2.1, 1.2.0, 1.1.7, 1.1.6 (global constraint requires ==1.1.5) trying: GPipe-1.1.5 trying: Vec-Boolean-1.0.6 (dependency of GPipe-1.1.5) next goal: Vec (dependency of GPipe-1.1.5) rejecting: Vec-1.0.5, 1.0.1, 1.0, 0.9.9, 0.9.8, 0.9.7 (conflict: GPipe => Vec==0.9.6) rejecting: Vec-0.9.6 (conflict: Vec-Boolean => Vec==1.0.1) rejecting: Vec-0.9.5, 0.9.4, 0.9.3, 0.9.2, 0.9.1, 0.9.0 (conflict: GPipe => Vec==0.9.6) Dependency tree exhaustively searched.