Resolving dependencies... Starting data-default-class-0.1.2.0 Starting network-3.1.4.0 Building data-default-class-0.1.2.0 Building network-3.1.4.0 Completed data-default-class-0.1.2.0 Completed network-3.1.4.0 Starting hocd-0.1.1.0 Building hocd-0.1.1.0 Failed to install hocd-0.1.1.0 Build log ( /home/builder/.cabal/logs/ghc-9.2.4/hocd-0.1.1.0-JuLRa1SBOdxBGU3XbvzCju.log ): cabal: Entering directory '/tmp/cabal-tmp-2781812/hocd-0.1.1.0' Configuring hocd-0.1.1.0... Preprocessing library for hocd-0.1.1.0.. Building library for hocd-0.1.1.0.. [1 of 5] Compiling HOCD.Error ( src/HOCD/Error.hs, dist/build/HOCD/Error.o, dist/build/HOCD/Error.dyn_o ) [2 of 5] Compiling HOCD.Types ( src/HOCD/Types.hs, dist/build/HOCD/Types.o, dist/build/HOCD/Types.dyn_o ) [3 of 5] Compiling HOCD.Command ( src/HOCD/Command.hs, dist/build/HOCD/Command.o, dist/build/HOCD/Command.dyn_o ) [4 of 5] Compiling HOCD.Monad ( src/HOCD/Monad.hs, dist/build/HOCD/Monad.o, dist/build/HOCD/Monad.dyn_o ) src/HOCD/Monad.hs:86:11: error: " Illegal equational constraint m ~ t m' (Use GADTs or TypeFamilies to permit this) " When checking the class method: getSocket :: forall (m :: * -> *). MonadOCD m => m Socket In the class declaration for MonadOCD | 86 | default getSocket | ^^^^^^^^^ cabal: Leaving directory '/tmp/cabal-tmp-2781812/hocd-0.1.1.0' Error: cabal: Some packages failed to install: hocd-0.1.1.0-JuLRa1SBOdxBGU3XbvzCju failed during the building phase. The exception was: ExitFailure 1