Token parse error on {-# UNPACK #-}

[Vlix]

Your environment

Output of haskell-language-server --probe-tools or haskell-language-server-wrapper --probe-tools:

haskell-language-server version: 0.8.0.0 (GHC: 8.6.5) (PATH: /home/flix/.config/Code/User/globalStorage/haskell.haskell/haskell-language-server-0.8.0-linux-8.6.5) (GIT hash: eb58f13f7b8e4f9bc771af30ff9fd82dc4309ff5)
Tool versions found on the $PATH
cabal:		2.4.1.0
stack:		2.5.1
ghc:		8.0.2

Which lsp-client do you use: VSCode
Describe your project (alternative: link to the project): https://github.com/yesodweb/wai/blob/master/warp/Network/Wai/Handler/Warp/Request.hs#L212
Contents of hie.yaml: none

Steps to reproduce

Expected behaviour

Should just parse the .hs file.

Actual behaviour

HLS fails to process the file. (Request.hs, see link to project)

Include debug information

LSP logs:

haskell-language-server-0.8.0-linux-8.6.5: Tokens.next failed to parse     {-# UNPACK #-} !Int -- running total byte count (excluding current header chunk) Parser did not consume entire stream, left: "!Int -- running total byte count (excluding current header chunk)"
CallStack (from HasCallStack):
  error, called at src/Ide/Plugin/Eval/Parse/Token.hs:134:19 in hls-eval-plugin-0.1.0.0-inplace:Ide.Plugin.Eval.Parse.Token

[Vlix]

Might be related to this one?
#1160 (comment)

[jneira]

I think the problem is related with parser errors coming from the eval plugin (take look to latest issues labeled with)
And hopefully it will be fixed by #1232

[konn]

I confirmed manually that this bug will be solved by #1232. I've just added the following test case to regression test:

{- | Won't panic on UNPACKs -}
module TUNPACK (THStatus(..)) where

type ByteString = String
type BSEndo = ByteString -> ByteString
type BSEndoList = [ByteString] -> [ByteString]

data THStatus = THStatus
    {-# UNPACK #-} !Int -- running total byte count
    BSEndoList -- previously parsed lines
    BSEndo -- bytestrings to be prepended

-- >>> "Yay! UNPACK pragma didn't do bad things!"

EDIT: ... And, of course, the above code fragments makes HLS 0.8.0, which doesn't include mentioned PR, hangs up as expected.