Reopening a buffer causes errors that have already been fixed

[suhdonghwi]

Steps to reproduce

1. Make any kind of error

   doi -- << Error here 
   putStrLn "Hello, world!"
   return 1

2. Fix it

   do -- << Error has been fixed
   putStrLn "Hello, world!"
   return 1

3. Close and reopen the source file, and edit anywhere

   do
   putStrLn "Hello, world!"
   return $ 1 + 1 -- << Edited here

4. Error which occured in Step 1 occurs again at the same location

   do -- << Error here!
   putStrLn "Hello, world!"
   return $ 1 + 1

---

This is my output of hie-wrapper --version:

Version 1.0.0.0, Git revision 4bec07d79cf77c8ee855957d20e315a89f799d75 (3745 commits) x86_64 ghc-8.6.5

[fendor]

Is there auto-save or something? Or is it unsaved?

[suhdonghwi]

I manually saved the file before closing and reopening it.

[fendor]

Can not reproduce with vscode on nixos with hie-8.6.5 on a cabal project. Can you add more information? What is the hie version, which one is used, what type of project, operating system, lsp-client and are you sure there are no other plugins active?

[suhdonghwi]

This is the output of hie --version:

Version 1.0.0.0, Git revision 4bec07d79cf77c8ee855957d20e315a89f799d75 (3745 commits) x86_64 ghc-8.6.5

I run it in Windows Subsystem for Linux, Ubuntu 18.04 LTS. Language server client is VSCode (WSL remote development) Haskell Language server extension. (But this problem also happens in neovim coc.nvim) There are no other Haskell related plugins active.

[fendor]

Can you provide the logs? If possible with --debug enabled. Either in vscode with File > Preferences > Settings > Haskell Language Server > Language Server Haskell > Trace: Server set to verbose or by invoking the hie/hie-wrapper process with the arguments hie --lsp --debug/hie-wrapper --lsp --debug

[suhdonghwi]

This is my log reproducing the bug: https://pastebin.com/ZRYwWn1H

[fendor]

And at the end errors were shown in the file Expr.hs?

[suhdonghwi]

Yes. But after reopening, if I edit anywhere and save the file again, errors disappear.

[fendor]

I can reproduce this error on windows as well, not reliably, but encountered it several times now. I suspect some caching issue, but I did not dig into it, yet.