Weird foreground color when LSP enabled

I write Haskell program in Nova, but observe strange foreground color when LSP is enabled (see the screenshots).

The two screenshots are taken with the default Bright/Dark editor themes. You can find that the foreground color under the cursor is really strange. Only when I move the caret to a specific position (in the screenshot, it’s Ln 8, Col 22, after the “=>” symbol), the issue occurs.

In the screenshot, I use the “inspecting” tool to show the color and hope it can be helpful.

It seems that the issue is related with LSP. If I disable the LSP extension, the issue doesn’t occur.


  • Nova 10.1
  • macOS 13.0
  • haskell-language-server-wrapper(haskell-language-server-wrapper) Version
  • aarch64 ghc-9.4.2

How to reproduce

  • Install the Haskell Tree Sitter extension from the extension library.

  • Download the Haskell LSP extension and the sample project from here.

  • Setup the Haskell environment. You can install it through:

    brew install haskell-stack
    brew install haskell-language-server
  • After installing the extension, fill the config of the LSP extension like:

  • Open the project free-monad in Nova. To make the LSP work, you may need to click Extensions -> Restart Haskell Language Server multiple times due to this bug. Make sure that the LSP hover works like:

  • Move the caret to “Ln 8, Col 22” of app/Main.hs, delete the “=>” characters and type “=>” again you can observe the issue like: