Well, a few moments ago, I was able to successfully run with: stack install ghcide --compiler ghc-8.8.1 and stack.yaml: extra-deps: - haskell-lsp-0.17.0.0 - haskell-lsp-types-0.17.0.0 resolver: nightly-2019-12-06 even if stack was complaining about versions of ghc and cabal. Thanks and regards Dusan Smells a bit like it only applies the MonadFail instance in ghc 8.8.1, but the build log said ghc 8.6 and implied MonadFailDesugaring enabled from the error message. On Tue, Dec 10, 2019 at 11:42 AM Vanessa McHale <vamchale@gmail.com[1]> wrote: cabal install ghcide -w ghc-8.8.1 seems to work, so I don’t think it’s ghcide precisely. Cheers, Vanessa On Dec 10, 2019, at 10:37 AM, Viktor Dukhovni <ietf-dane@dukhovni.org[2]> wrote: On Dec 10, 2019, at 11:03 AM, Dušan Kolář <kolar@fit.vut.cz[3]> wrote: -- 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? https://github.com/digital-asset/ghcide/commit/ e78e1638ea00af7c5bf4fdbae245413eafed4248[4] http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe[5] _http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe_ brandon s allbery kf8nh allbery.b@gmail.com[6] -- Dusan Kolar tel: +420 54 114 1238 UIFS FIT VUT Brno fax: +420 54 114 1270 Bozetechova 2 e-mail: kolar@fit.vut.cz Brno 612 66 Czech Republic -- -------- [1] mailto:vamchale@gmail.com [2] mailto:ietf-dane@dukhovni.org [3] mailto:kolar@fit.vut.cz [4] https://github.com/digital-asset/ghcide/commit/ e78e1638ea00af7c5bf4fdbae245413eafed4248 [5] http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe [6] mailto:allbery.b@gmail.com