Description
Summary
I am trying to get a minimal example of LiquidHaskell working with HLS, and I'm running into the following issue:
The haskell-language-server-wrapper command produces an inappropriate compilation error:
Unknown type constructor `Pos`
matchTyCon: Pos
The stack repl command, on the other hand, compiles successfully without producing the error (this is the correct behavior, as the code itself is correct).
hie-bios produces the error despite the project containing a hie.yaml file with these contents:
cradle:
stack:My understanding was that this was supposed to make hie-bios build "the same way" that Stack does. Why might hie-bios build differently than Stack, even when the hie.yaml file is present?
Steps to re-create
Platform: Arch Linux
Install the following via ghcup:
- HLS 2.6.0.0
- GHC 9.8.1
- Stack 3.1.1
- cabal 3.12.1
Example project: git clone https://github.com/ucsd-progsys/lh-plugin-demo.git
Replace the contents of the stack.yaml file with the following:
resolver: nightly-2024-01-26
system-ghc: true
packages:
- .
extra-deps:
- rest-rewrite-0.4.3
- smtlib-backends-0.3
- smtlib-backends-process-0.3
- store-0.7.18
- store-core-0.4.4.7
- liquidhaskell-0.9.8.1
- liquidhaskell-boot-0.9.8.1
- liquid-fixpoint-0.9.6.3
- liquid-prelude-0.9.2.8.1@rev:1
- liquid-vector-0.13.1.0.1
nix:
packages: [cacert, git, hostname, z3]Create a top-level hie.yaml file with the following contents:
cradle:
stack:Replace the contents of src/Demo/Client.hs with the following:
{-# OPTIONS_GHC -fplugin=LiquidHaskell #-}
module Demo.Client where
import Demo.Lib
{-@ posId :: Pos -> Pos @-}
posId :: Int -> Int
posId = idAt this point,
stack build compiles with no errors.
stack ghci compiles with no errors.
stack repl compiles with no errors.
haskell-language-server-wrapper produces a compilation error:
Unknown type constructor `Pos`
matchTyCon: Pos
Why might hie-bios build differently than Stack, even when the hie.yaml file is present? Thank you in advance for your help!
Extra context
I was able to recreate this issue with ghcid.
The command ghcid fails to compile with the same error that hie-bios is producing.
The command ghcid "--command=stack ghci" compiles with no errors, giving the All good message. This does not immediately help me resolve the issue with hie-bios, though.