I am using VSCode with the Haskell extension. I have ghcup installed with the following installed:
Stack 2.7.5
HLS 1.7.0.0
Cabal 3.6.2.0
GHC 9.0.2 (set)
GHC 8.10.7
If I have a stack.yaml with lts-18.28 the haskell-language-server boots and the hover works. If I have stack.yaml with lts-19.16 the haskell-language-server crashes.
What do I have to do to get the haskell-language-server to work with lts-19.16?
EDIT
It seems that Ismor's comment to add "system-ghc: true" to the stack.yaml file is on the right lines.
Now nightly-2022-06-06 (with ghc-9.2.2) works.
It seems there is some issue with the 9.0.2 version that stack uses not being the same as HLS, so lts-19.16 still does not work.
Also, nightly-2022-07-30 does not work, but the HLS web pages (https://haskell-language-server.readthedocs.io/en/latest/supported-versions.html) say that ghc-9.2.3 is only partially supported.
Anyway, I can now choose ghc-8.10.7 or ghc-9.2.2 and still use HLS in vscode so that's good enough for me.
EDIT2
See: "ghcup compile hls" here https://www.haskell.org/ghcup/guide/#hls
and see here: https://docs.haskellstack.org/en/stable/Stack_and_VS_Code/