Resolving dependencies... Configuring mtl-2.2.1... Configuring primitive-0.6.2.0... Building mtl-2.2.1... Building primitive-0.6.2.0... Configuring random-1.1... Installed mtl-2.2.1 Building random-1.1... Installed primitive-0.6.2.0 Installed random-1.1 Configuring tf-random-0.5... Building tf-random-0.5... Installed tf-random-0.5 Configuring QuickCheck-2.9.2... Building QuickCheck-2.9.2... Installed QuickCheck-2.9.2 Configuring Operads-0.5... Building Operads-0.5... Failed to install Operads-0.5 Build log ( /home/builder/.cabal/logs/Operads-0.5.log ): cabal: Entering directory '/tmp/cabal-tmp-29996/Operads-0.5' Configuring Operads-0.5... Building Operads-0.5... Preprocessing library Operads-0.5... [1 of 6] Compiling Math.Operad.PPrint ( Math/Operad/PPrint.hs, dist/build/Math/Operad/PPrint.o ) [2 of 6] Compiling Math.Operad.OrderedTree ( Math/Operad/OrderedTree.hs, dist/build/Math/Operad/OrderedTree.o ) Math/Operad/OrderedTree.hs:60:10: error: • Could not deduce (Applicative (PreDecoratedTree a)) arising from the superclasses of an instance declaration from the context: (Ord a, Show a) bound by the instance declaration at Math/Operad/OrderedTree.hs:60:10-54 • In the instance declaration for ‘Monad (PreDecoratedTree a)’ cabal: Leaving directory '/tmp/cabal-tmp-29996/Operads-0.5' cabal: Error: some packages failed to install: Operads-0.5 failed during the building phase. The exception was: ExitFailure 1