What is needed to effectively report an issue?

[levans]

I have a project in VSCode that crashes HLS 0.9.0 consistently.
I get "The Haskell () server crashed 5 times in the last 3 minutes. The server will not be restarted."

I streamed the messages to a file (attached), but that doesn't look too interesting to me.

Perhaps someone could advise how I could produce more interesting tracing/logging to help identify this issue. Of course, I could also try to narrow down the condition in this project that is causing the failure (which I might also try if I can set aside the time to experiment).

vccode.log

[jhrcek]

In VSCode the easiest way to find out why HLS is crashing is to open Output tab (In top menu select View > Output), in the Output Tab that opens, select "Haskell (yourproject)" which should give you enough info about why it's crashing. You might need to do CTRL+Shift+P > "Haskell: Restart Haskell LSP Server" to trigger the restart attempts and see the crash reports.

If that doesn't give you enough info, you can also go to Haskell extension settings and enable
Haskell > Trace: Server and switch it to messages, which will give you all the json RPC messages being passed between client (vscode haskell extension) and server (haskell-language-server). Note that after enabling this latter setting you'll need to restart vscode for it to have an effect. But in your case (hls crashing) I think the first step (opening the Output tab for hls) should be enough.

For more thoubleshooting tips see https://github.com/haskell/haskell-language-server#troubleshooting in Readme.

[levans]

Ah, hadn't noticed the drop down to select the output buffer. Thanks!

My output is:
haskell-language-server version: 0.9.0.0 (GHC: 8.8.4) (PATH: /Users/luke/Library/Application Support/Code/User/globalStorage/haskell.haskell/haskell-language-server-0.9.0-darwin-8.8.4) (GIT hash: 46d2a3d)
Starting (haskell-language-server)LSP server...
with arguments: LspArguments {argLSP = True, argsCwd = Nothing, argFiles = [], argsShakeProfiling = Nothing, argsTesting = False, argsExamplePlugin = False, argsDebugOn = False, argsLogFile = Nothing, argsThreads = 0, argsProjectGhcVersion = False}
with plugins: [PluginId "brittany",PluginId "class",PluginId "eval",PluginId "floskell",PluginId "fourmolu",PluginId "ghcide-code-actions",PluginId "ghcide-completions",PluginId "ghcide-hover-and-symbols",PluginId "ghcide-type-lenses",PluginId "haddockComments",PluginId "hlint",PluginId "importLens",PluginId "moduleName",PluginId "ormolu",PluginId "pragmas",PluginId "retrie",PluginId "splice",PluginId "stylish-haskell",PluginId "tactic"]
in directory: /Users/luke/Projects/spark
If you are seeing this in a terminal, you probably should have run ghcide WITHOUT the --lsp option!
Started LSP server in 0.00s
2021-02-02 21:33:50.356268 [ThreadId 37] - Registering ide configuration: IdeConfiguration {workspaceFolders = fromList [NormalizedUri (-8627624539692671696) "file:///Users/luke/Projects/spark"], clientSettings = hashed Nothing}
2021-02-02 21:33:50.357306 [ThreadId 37] - Configuration changed: Object (fromList [("haskell",Object (fromList [("logFile",String ""),("updateBehavior",String "keep-up-to-date"),("hlintOn",Bool True),("formatOnImportOn",Bool True),("indentationRules",Object (fromList [("enabled",Bool True)])),("liquidOn",Bool False),("languageServerVariant",String "haskell-language-server"),("serverExecutablePath",String ""),("diagnosticsOnChange",Bool True),("completionSnippetsOn",Bool True),("maxNumberOfProblems",Number 100.0),("formattingProvider",String "ormolu"),("trace",Object (fromList [("server",String "off")]))]))])
2021-02-02 21:33:50.357801 [ThreadId 37] - Opened text document: file:///Users/luke/Projects/spark/src/Import.hs
2021-02-02 21:33:50.358532 [ThreadId 108] - hlint:getIdeas:file:NormalizedFilePath "/Users/luke/Projects/spark/src/Import.hs"
2021-02-02 21:33:50.359436 [ThreadId 111] - Consulting the cradle for "src/Import.hs"
Output from setting up the cradle Cradle {cradleRootDir = "/Users/luke/Projects/spark", cradleOptsProg = CradleAction: Stack}

Building all executables for `spark' once. After a successful build of all of them, only specified executables will be rebuilt.
spark> configure (lib + exe)
Configuring spark-0.1.0...
spark> initial-build-steps (lib + exe)
The following GHC options are incompatible with GHCi and have not been passed to it: -O2
Configuring GHCi with the following packages: spark
/Users/luke/Projects/spark/.stack-work/install/x86_64-osx/175e85e7391997f618a3e9d69820799746a20acc1b2f250068a7f1daadbd2998/8.8.4/pkgdb:/Users/luke/.stack/snapshots/x86_64-osx/175e85e7391997f618a3e9d69820799746a20acc1b2f250068a7f1daadbd2998/8.8.4/pkgdb:/Users/luke/.stack/programs/x86_64-osx/ghc-8.8.4/lib/ghc-8.8.4/package.conf.d
2021-02-02 21:33:54.712638 [ThreadId 111] - Using interface files cache dir: ghcide
2021-02-02 21:33:54.712708 [ThreadId 111] - Making new HscEnv[main]
2021-02-02 21:33:54.776699 [ThreadId 242] - hlint:getIdeas:file:NormalizedFilePath "/Users/luke/Projects/spark/src/Import.hs"
2021-02-02 21:33:54.781593 [ThreadId 301] - finish: getSession (took 0.01s)
2021-02-02 21:33:54.781598 [ThreadId 308] - finish: ModuleName.ghcSession (took 0.01s)
2021-02-02 21:33:54.782882 [ThreadId 306] - finish: ModuleName.GetParsedModule (took 0.00s)
2021-02-02 21:33:54.782952 [ThreadId 302] - finish: importLens (took 0.01s)
2021-02-02 21:33:54.782986 [ThreadId 306] - finish: CodeAction (took 0.01s)
2021-02-02 21:33:54.782996 [ThreadId 304] - finish: HaddockComments.GetAnnotatedParsedSource (took 0.01s)
2021-02-02 21:33:54.783024 [ThreadId 305] - finish: splice.codeAction.GitHieAst (took 0.01s)
2021-02-02 21:33:54.783056 [ThreadId 248] - finish: Outline (took 0.01s)
2021-02-02 21:33:54.783083 [ThreadId 306] - finish: addPragma (took 0.01s)
2021-02-02 21:33:54.782943 [ThreadId 301] - hlint:getIdeas:setExtensions:[Cpp,OverlappingInstances,UndecidableInstances,IncoherentInstances,UndecidableSuperClasses,MonomorphismRestriction,MonoPatBinds,MonoLocalBinds,RelaxedPolyRec,ExtendedDefaultRules,ForeignFunctionInterface,UnliftedFFITypes,InterruptibleFFI,CApiFFI,GHCForeignImportPrim,JavaScriptFFI,ParallelArrays,TemplateHaskell,TemplateHaskellQuotes,ImplicitParams,ImplicitPrelude,ScopedTypeVariables,AllowAmbiguousTypes,UnliftedNewtypes,BangPatterns,TypeFamilies,TypeFamilyDependencies,TypeInType,OverloadedStrings,OverloadedLists,NumDecimals,DisambiguateRecordFields,RecordWildCards,RecordPuns,ViewPatterns,GADTs,GADTSyntax,NPlusKPatterns,DoAndIfThenElse,BlockArguments,RebindableSyntax,ConstraintKinds,PolyKinds,DataKinds,InstanceSigs,ApplicativeDo,StandaloneDeriving,DeriveDataTypeable,AutoDeriveTypeable,DeriveFunctor,DeriveTraversable,DeriveFoldable,DeriveGeneric,DefaultSignatures,DeriveAnyClass,DeriveLift,DerivingStrategies,DerivingVia,TypeSynonymInstances,FlexibleContexts,FlexibleInstances,ConstrainedClassMethods,MultiParamTypeClasses,NullaryTypeClasses,FunctionalDependencies,UnicodeSyntax,ExistentialQuantification,MagicHash,EmptyDataDecls,KindSignatures,RoleAnnotations,ParallelListComp,MonadComprehensions,GeneralizedNewtypeDeriving,PostfixOperators,TupleSections,PatternGuards,LiberalTypeSynonyms,RankNTypes,ImpredicativeTypes,TypeOperators,ExplicitNamespaces,PackageImports,ExplicitForAll,AlternativeLayoutRuleTransitional,DatatypeContexts,NondecreasingIndentation,RelaxedLayout,TraditionalRecordSyntax,LambdaCase,MultiWayIf,BinaryLiterals,HexFloatLiterals,DuplicateRecordFields,OverloadedLabels,EmptyCase,PatternSynonyms,PartialTypeSignatures,NamedWildCards,TypeApplications,Strict,StrictData,MonadFailDesugaring,EmptyDataDeriving,NumericUnderscores,QuantifiedConstraints,ImportQualifiedPost,CUSKs,StandaloneKindSignatures,QuasiQuotes,StarIsType]
2021-02-02 21:33:55.486196 [ThreadId 1770] - finish: CodeAction:PackageExports (took 0.70s)
[Error - 9:33:56 PM] Connection to server got closed. Server will not be restarted.
[Error - 9:33:56 PM] Request textDocument/codeAction failed.
Error: Connection got disposed.
at Object.dispose (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:90964)
at Object.dispose (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:74243)
at D.handleConnectionClosed (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:74417)
at D.handleConnectionClosed (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:247:9685)
at t (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:72568)
at n.invoke (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:233221)
at i.fire (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:233951)
at G (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:82879)
at n.invoke (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:233221)
at i.fire (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:233951)
at u.fireClose (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:252684)
at Socket. (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:253441)
at Socket.emit (events.js:228:7)
at Pipe. (net.js:664:12)
[Error - 9:33:56 PM] Request textDocument/codeLens failed.
Error: Connection got disposed.
at Object.dispose (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:90964)
at Object.dispose (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:74243)
at D.handleConnectionClosed (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:74417)
at D.handleConnectionClosed (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:247:9685)
at t (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:72568)
at n.invoke (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:233221)
at i.fire (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:233951)
at G (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:82879)
at n.invoke (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:233221)
at i.fire (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:233951)
at u.fireClose (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:252684)
at Socket. (/Users/luke/.vscode/extensions/haskell.haskell-1.2.0/dist/extension.js:1:253441)
at Socket.emit (events.js:228:7)
at Pipe. (net.js:664:12)

I'll google on this a bit to see if it's a known issue.

[jneira]

Hi, thanks to ask it, it is a common doubt between hls users and @jhrcek's answer is great for future reference (maybe we should update troubleshooting instructions in the readme with vscode specific notes? i think so)

When you fill a new issue there is some instructions in the template that may be help too, take a look and dont hesitate if you find them confusing or incomplete: https://github.com/haskell/haskell-language-server/issues/new

About your concrete error, unfortunately is not clear the root cause as the server is crashing, i guess the cause can be the eval plugin as lately is causing server crashes for some source codes (usually related with comments):

• could you enable Haskell > Trace: Server and switch it to messages? as suggested by @jhrcek, it will be log additional traces that may help to hunt the bug
• a link to the source file causing the chrash may help too

[fendor]

@levans Pretty sure this should be a proper bug report now.

I have a similar issue, which I can even re-produce with haskell-language-server --debug <some-filepath>, but so far, I don't think we know why this happens...

[levans]

@fendor I've just tried opening a range of other projects in Code with HLS installed and this is happening with most of them (but not all). I'll try to spot the difference - but there's Template Haskell in many and of course the usual smattering of language extensions on/off (set as default package.yaml, or some in .cabal).