Hello Café, Using stack, I've tried stack install ghcide, it reported to put the following into my global extra-deps: - haskell- lsp-0.17.0.0@sha256:ddfcc2798f04bcb1ec20fafc02c03faa197322192578e879cef5852 aba43ebcb,5264 - haskell-lsp- types-0.17.0.0@sha256:9078237412d0596a7d09d432389c8fa21d6f3e21ed2ed761b3 093a21607d6c28,2941 - hie- bios-0.2.1@sha256:5f98a3516ce65e0a3ffd88bf6fb416b04cc084371d0fbf0e1762780d e1d652ce,3219 - rope-utf16- splay-0.3.1.0@sha256:15a53c57f8413d193054bb5f045929edae3b2669def4c6af6319 7b30dc1d5003,2029 Nevertheless, the build failed anyway: stack install ghcide ghcide> configure ghcide> Configuring ghcide-0.0.4... ghcide> build ghcide> Preprocessing library for ghcide-0.0.4.. ghcide> Building library for ghcide-0.0.4.. ghcide> [ 1 of 33] Compiling Development.IDE.Core.Debouncer ghcide> [ 2 of 33] Compiling Development.IDE.Core.PositionMapping ghcide> [ 3 of 33] Compiling Development.IDE.GHC.Compat ghcide> [ 4 of 33] Compiling Development.IDE.GHC.CPP ghcide> [ 5 of 33] Compiling Development.IDE.Spans.Type ghcide> [ 6 of 33] Compiling Development.IDE.Types.Location ghcide> [ 7 of 33] Compiling Development.IDE.Types.Diagnostics ghcide> [ 8 of 33] Compiling Development.IDE.LSP.Protocol ghcide> [ 9 of 33] Compiling Development.IDE.GHC.Util ghcide> [10 of 33] Compiling Development.IDE.GHC.Orphans ghcide> [11 of 33] Compiling Development.IDE.Import.DependencyInformation ghcide> [12 of 33] Compiling Development.IDE.GHC.Error ghcide> [13 of 33] Compiling Development.IDE.Import.FindImports ghcide> [14 of 33] Compiling Development.IDE.GHC.Warnings ghcide> [15 of 33] Compiling Development.IDE.Core.Preprocessor ghcide> [16 of 33] Compiling Development.IDE.Core.RuleTypes ghcide> [17 of 33] Compiling Development.IDE.Types.Logger ghcide> [18 of 33] Compiling Development.IDE.Types.Options ghcide> [19 of 33] Compiling Development.IDE.Core.Shake ghcide> ghcide> /tmp/stack204611/ghcide-0.0.4/src/Development/IDE/Core/Shake.hs:106:5: error: ghcide> • No instance for (Control.Monad.Fail.MonadFail Rules) ghcide> arising from a do statement ghcide> with the failable pattern ‘Just x’ ghcide> • In a stmt of a 'do' block: ghcide> Just x <- getShakeExtraRules @ShakeExtras ghcide> In the expression: ghcide> do Just x <- getShakeExtraRules @ShakeExtras ghcide> return x ghcide> In an equation for ‘getShakeExtrasRules’: ghcide> getShakeExtrasRules ghcide> = do Just x <- getShakeExtraRules @ShakeExtras ghcide> return x ghcide> | ghcide> 106 | Just x <- getShakeExtraRules @ShakeExtras ghcide> | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ghcide> -- While building package ghcide-0.0.4 using: /home/kolar/.stack/setup-exe-cache/x86_64-linux-tinfo6/Cabal- simple_mPHDZzAJ_2.4.0.1_ghc-8.6.3 --builddir=.stack-work/dist/x86_64-linux-tinfo6/ Cabal-2.4.0.1 build --ghc-options " -fdiagnostics-color=always" Process exited with code: ExitFailure 1 Does that mean the ghcide is broken? Or am I doing something wrong? Best regards, Dusan