Applying hints fails with HLS 1.0.0

[lylek]

With HLS 0.9.0, applying hints would hang. So I patiently waited for the next release. Now with HLS 1.0.0, it fails instead of hanging. Here's a section of debug output from when I tried to apply a hint. You will see some errors therein, one of which says to "please report". I see that there's a parse error when the server unexpectedly returned a Null. There's also an error about a missing file. Not sure what's most relevant but I hope this helps diagnose the problem. Not sure whether it's an issue with the extension or with the server.

2021-02-25 11:07:42.622326 [ThreadId 5] DEBUG haskell-lsp.parseOne:	---> {"jsonrpc":"2.0","id":78,"method":"workspace/executeCommand","params":{"command":"27652:hlint:applyOne","arguments":[{"file":"file:///Users/lyle/ExaTMS/src/TripShot/Bz/OnDemand/Scheduling/RideCandidates.hs","start_pos":{"character":38,"line":249},"hintTitle":"Use <>"}]}}
2021-02-25 11:07:42.622967 [ThreadId 7] DEBUG haskell-lsp.sendServer:	<--2--{"id":60,"method":"window/workDoneProgress/create","params":{"token":5},"jsonrpc":"2.0"}
2021-02-25 11:07:42.622893 [ThreadId 11743] INFO hls:	hlint:applyOneCmd:file=NormalizedFilePath "/Users/lyle/ExaTMS/src/TripShot/Bz/OnDemand/Scheduling/RideCandidates.hs"
2021-02-25 11:07:42.623077 [ThreadId 7] DEBUG haskell-lsp.sendServer:	<--2--{"method":"$/progress","params":{"token":5,"value":{"title":"Applying hint: Use <>","kind":"begin","cancellable":true}},"jsonrpc":"2.0"}
2021-02-25 11:07:42.623197 [ThreadId 5] DEBUG haskell-lsp.parseOne:	---> {"jsonrpc":"2.0","id":60,"result":null}
2021-02-25 11:07:42.623362 [ThreadId 11744] INFO hls:	hlint:getIdeas:file:NormalizedFilePath "/Users/lyle/ExaTMS/src/TripShot/Bz/OnDemand/Scheduling/RideCandidates.hs"
2021-02-25 11:07:42.623408 [ThreadId 7] DEBUG haskell-lsp.sendServer:	<--2--{"method":"window/logMessage","params":{"message":"haskell-lsp:incoming message parse error. {\"jsonrpc\":\"2.0\",\"id\":60,\"result\":null} Error in $.result: parsing () failed, expected Array, but encountered Null\n","type":1},"jsonrpc":"2.0"}
2021-02-25 11:07:42.623526 [ThreadId 11744] INFO hls:	finish: applyHint (took 0.00s)
[Error - 11:07:42 AM] haskell-lsp:incoming message parse error. {"jsonrpc":"2.0","id":60,"result":null} Error in $.result: parsing () failed, expected Array, but encountered Null

2021-02-25 11:07:42.623528 [ThreadId 11743] INFO hls:	applyHint:apply=[[Replace {rtype = Expr, pos = SrcSpan {startLine = 250, startCol = 39, endLine = 250, endCol = 126}, subts = [("a",SrcSpan {startLine = 250, startCol = 39, endLine = 250, endCol = 74}),("b",SrcSpan {startLine = 250, startCol = 78, endLine = 250, endCol = 126})], orig = "a <> b"}]]
2021-02-25 11:07:43.037141 [ThreadId 11746] INFO hls:	finish: applyHint (took 0.00s)
2021-02-25 11:07:43.037224 [ThreadId 11748] INFO hls:	finish: applyHint (took 0.00s)
2021-02-25 11:07:43.037321 [ThreadId 11750] INFO hls:	finish: applyHint (took 0.00s)
Missing file: /Users/runner/.ghcup/ghc/8.10.4/lib/ghc-8.10.4/settings
2021-02-25 11:07:43.037602 [ThreadId 7] DEBUG haskell-lsp.sendServer:	<--2--{"method":"$/progress","params":{"token":5,"value":{"kind":"end"}},"jsonrpc":"2.0"}
2021-02-25 11:07:43.037611 [ThreadId 11740] ERROR hls:	Unexpected exception on request, please report!
Exception: ExitFailure 1
[Error - 11:07:43 AM] Request workspace/executeCommand failed.
  Message: ExitFailure 1
  Code: -32603 
2021-02-25 11:07:43.037821 [ThreadId 7] DEBUG haskell-lsp.sendServer:	<--2--{"id":78,"jsonrpc":"2.0","error":{"message":"ExitFailure 1","code":-32603}}

[jneira]

I am afraid this is another manifestation of #591
As mentioned there the workaround is create a symlink from the missing path to the real path of your ghc installation

[jneira]

I am gonna close this one if you don't mind, you can track the solution in the mentioned issue #591

[lylek]

Thanks, got the workaround to work - though it took me a bit of figuring of where my GHC installation was and how to properly symlink it.