HLS gets stuck if session setup fails for any reason

[fendor]

When the session set up fails, then the HLS thread crashes and will not be restarted.

I added a catch to the session setup, logging the error. After the error is thrown, HLS appears to be completely stuck.

Example trace:

2024-06-27T15:50:04.706392Z | Debug | stack setup --silent
2024-06-27T15:50:05.070647Z | Debug | stack exec ghc -- --numeric-version
[Trace - 17:50:05] Received notification '$/progress'.
2024-06-27T15:50:05.070866Z | Debug | Session loading result: Right (ComponentOptions {componentOptions = ["-i","-odir=/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/.stack-work/odir","-hidir=/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/.stack-work/odir","-hide-all-packages","-XGHC2021","-i/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/explainable/.stack-work/dist/x86_64-linux/ghc-9.6.5/build/explainable-exe","-i/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/explainable/app","-i/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/explainable/.stack-work/dist/x86_64-linux/ghc-9.6.5/build/explainable-exe/autogen","-i/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/explainable/.stack-work/dist/x86_64-linux/ghc-9.6.5/build/global-autogen","-i/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/explainable/.stack-work/dist/x86_64-linux/ghc-9.6.5/build/explainable-exe/explainable-exe-tmp","-stubdir=/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/explainable/.stack-work/dist/x86_64-linux/ghc-9.6.5/build","-package-id=QuickCheck-2.14.3-7WdOShjYsRTQ5DwHd4Gtb","-package-id=aeson-2.1.2.1-F3hDGK91Wx42rTliAGkUq","-package-id=base-4.18.2.1","-package-id=boxes-0.1.5-C5KrYVvXsQG8cA3g3hv7uh","-package-id=bytestring-0.11.5.3","-package-id=containers-0.6.7","-package-id=directory-1.3.8.4","-package-id=effectful-2.3.0.0-3V3X0RsGjod7jCYr6Wti","-package=explainable-0.1.0.0","-package-id=fgl-5.8.2.0-85Qkt6u9x2z5NSStlZTxr6","-package-id=filepath-1.4.300.1","-package-id=graphviz-2999.20.2.0-64QWSEOt6dh36pYl7wtiek","-package-id=hspec-2.11.9-4wTKmuILwwUEq4fqjWEoZg","-package-id=lens-5.2.3-G0LWaXeEo0UDN0iZ5b4CcG","-package-id=megaparsec-9.5.0-D2uz1Hosetnt14WoHo7Ea","-package-id=mtl-2.3.1","-package-id=numeric-extras-0.1-LgQWj8Z8pmPKPk9V7di9SO","-package-id=openapi3-3.2.4-8OMi17vBjaf4LVrZUUMg5C","-package-id=optparse-applicative-0.18.1.0-KKw4zpvajYE9Msk9T1Ikpr","-package-id=parsec-3.1.16.1","-package-id=parser-combinators-1.3.0-20UTEUZ5CKDJdRu747ID48","-package-id=pcre-heavy-1.0.0.3-6TcStAgMWa5DIw1maQ5Z9t","-package-id=prettyprinter-1.7.1-60yVE7QePDs8FHIPsacPFF","-package-id=prettyprinter-interp-0.2.0.0-5T6TkajMYyiGGBwTvUfYk3","-package-id=quickcheck-instances-0.3.30-KikxF4MVt6S9929xX2tsLH","-package-id=scientific-0.3.7.0-7ih7NuxY8AT9Jmz8D0EZgy","-package-id=servant-0.20.1-6oNY4TzoYI63JyjY0sLHWq","-package-id=servant-openapi3-2.0.1.6-FQDfjqNkbplHlJNuW2u5gJ","-package-id=servant-server-0.20-DtT9lGedLuzJu9wRxFzqT4","-package-id=servant-swagger-ui-0.3.5.5.0.0-7dLcEYwWM2i53FUQ5BcZKg","-package-id=string-interpolate-0.3.3.0-FdcmmUSqZzY5RLaNHS2LG4","-package-id=text-2.0.2","-package-id=transformers-0.6.1.0","-package-id=unordered-containers-0.2.20-ED65WLJGTgHKKHANJYMwZr","-package-id=wai-3.2.4-6PqrRGq5uVCcx5GJE074k","-package-id=wai-logger-2.4.0-K2ThryFHdX15W72WGMUmgk","-package-id=warp-3.3.31-BQkvXyHwhQ02XfAxYTn4Y8","-Wall","-Wcompat","-Widentities","-Wincomplete-record-updates","-Wincomplete-uni-patterns","-Wmissing-export-lists","-Wmissing-home-modules","-Wpartial-fields","-Wredundant-constraints","-Wall","-rtsopts","-with-rtsopts=-N","-fwrite-ide-info","-optP-include","-optP/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/.stack-work/ghci/69ba514d/cabal_macros.h","-ghci-script=/home/hugin/.cache/stack/ghci-script/3484a1de/ghci-script","-package-db","/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/.stack-work/install/x86_64-linux/b436016af794c3fa6328af8976a3bc0bcf56a1156d8c4cc82a3d6f67ee396726/9.6.5/pkgdb","-package-db","/home/hugin/.stack/snapshots/x86_64-linux/b436016af794c3fa6328af8976a3bc0bcf56a1156d8c4cc82a3d6f67ee396726/9.6.5/pkgdb","-package-db","/home/hugin/.ghcup/ghc/9.6.5/lib/ghc-9.6.5/lib/package.conf.d"], componentRoot = "/home/hugin/Documents/haskell/cclaw/dsl/lib/haskell/explainable", componentDependencies = ["explainable/explainable.cabal","explainable/package.yaml","stack.yaml"]},"/home/hugin/.ghcup/ghc/9.6.5/lib/ghc-9.6.5/lib","9.6.5")
2024-06-27T15:50:05.083638Z | Info | Interface files cache directory: /home/hugin/.cache/ghcide/main-d8039823af9b65242e8d42ce90d5528ab12596c0-d8039823af9b65242e8d42ce90d5528ab12596c0
2024-06-27T15:50:05.090341Z | Info | Making new HscEnv. In-place unit ids: [ main-d8039823af9b65242e8d42ce90d5528ab12596c0 ]
cannot satisfy -package explainable-0.1.0.0
    (use -v for more information)

The error itself is a manifestation of commercialhaskell/stack#5380, not relevant to this issue, though.

However, we should catch such errors and handle them gracefully.

[soulomoon]

We might be able to capture it and throw the error to the rule evaluation