Korny Sietsma (Aug 30 2024 at 18:17): Korny Sietsma (Aug 30 2024 at 18:17):Hey folks - just trying to get started (fetched a new nightly) on an M3 Mac, and I can run the compiler and samples OK, but the language server in VSCode errors with:
[Error - 19:09:58] Client roc-lang: connection to server is erroring.
Header must provide a Content-Length property.
{"{\"jsonrpc\"":"\"2.0\",\"result\":null,\"id\":2}Content-Length: 180"}
Shutting down server.
If I run the binary language server from a terminal I get something similar:
./roc_language_server
[2024-08-30T18:10:23Z ERROR tower_lsp::transport] failed to decode message: missing required `Content-Length` header
Content-Length: 75
{"jsonrpc":"2.0","error":{"code":-32700,"message":"Parse error"},"id":null}%
Any thoughts? I searched for issues but found nothing similar.
Anton (Aug 30 2024 at 18:22):Hi @Korny Sietsma,
Can you try the steps here?
Anton (Aug 30 2024 at 18:23):I suspect not all these steps are necessary but doing them all will probably fix it.
Korny Sietsma (Aug 30 2024 at 18:50):Ha - I started looking at that and saw
I needed to reinstall the extention after adding the configuration, and manually re-start the language server, and then it worked!
I'd already tried stopping and starting VSCode - but not just the language server. I stopped and started the language server - and now it works!
Last updated: Jul 26 2025 at 12:14 UTC