Does the version of the Haskell Language Server used include the hls-eval-plugin? If not, could it?

[toddobryan]

I'm trying to do this in VSCode:

https://haskell-language-server.readthedocs.io/en/latest/features.html#evaluation-code-snippets-in-comments

It doesn't seem to work.

Does the version of the HLS that the extension uses include this plugin? Is there a way for me to add it? Would you consider including it by default?

[jhrcek]

What version of GHC are you trying to use HLS with?
Based on the plugin support tiers eval plugin is not yet working with ghc 9.4 and newer in the latest release of hls.

However just a few days ago this PR was merged which should make it work with ghc 9.4: haskell/haskell-language-server#3391
You could either wait for new release of HLS containing this change to be released, or you could install hls from source using ghcup. Something like ghcup compile hls -g master --ghc 9.4.4 --cabal-update

[toddobryan]

I got an error trying to run that.

[ Info  ] Fetching git repo https://github.com/haskell/haskell-language-server.git at ref master (this may take a while)
[ Info  ] Examining git ref master
[ ...   ]   HLS version (from cabal file): 1.9.1.0
[ ...   ]   commit hash: 50799fecb450babf252ac87986a1a073aa709ae9
[ Info  ] Building HLS 1.9.1.0 for GHC version 9.4.4
[ cabal ] 
[ cabal ] Error: cabal: Failed to build zlib-0.6.3.0 (which is required by
[ cabal ] exe:haskell-language-server-wrapper from haskell-language-server-1.9.1.0 and
[ cabal ] exe:haskell-language-server from haskell-language-server-1.9.1.0). See the
[ cabal ] build log above for details.
[ cabal ] 

Relative Haskell newbie here, so how do I specify which version of GHC to use?

[hasufell]

You need zlib-dev package.

The CI shows what you need:

https://github.com/haskell/haskell-language-server/blob/81dcefc48db979f3eebc065e766e1d1239ad24eb/.github/workflows/release.yaml#L66

[jhrcek]

Relative Haskell newbie here, so how do I specify which version of GHC to use?

Did you setup your haskell environment using ghcup (recommended)?
You can check using ghcup list or using its terminal UI ghcup tui.

If not, it dependes on whether you're using stack or cabal to build your project.
If you're using cabal, you're most likely using GHC that's on your path.
Just run ghc --version

If you're using stack, the version of ghc you're using depends on your project's stack configuration.
Go to your project directory containing stack.yaml and run stack ghc -- --version

[fendor]

Closing since I think this is resolved