"connection to server is erroring. Header must provide a Content-Length property” errors in VS Code

[snej]

• Installed Roc nightly on my MacBook Pro
• Installed the VS Code extension
• Opened a VS code window, pasted in the first “Building An Application” tutorial example, and saved it as “hello.roc"
• Several error notifications popped up:

Client roc-lang: connection to server is erroring. Header must provide a Content-Length property. {"downloading \u001b[36mhttps":"//github.com/roc-lang/basic-cli/releases/download/0.10.0/vNe6s9hWzoTZtFmNkvEICPErI9ptji_ySjicO6CkucY.tar.br\u001b[0m\n into /Users/snej/.cache/roc/packages\n\nContent-Length: 38"} Shutting down server.

Client roc-lang: connection to server is erroring. Header must provide a Content-Length property. {"{\"jsonrpc\"":"\"2.0\",\"result\":null,\"id\":1}Content-Length: 38"} Shutting down server.

Client roc-lang: connection to server is erroring. Header must provide a Content-Length property. {"{\"jsonrpc\"":"\"2.0\",\"result\":null,\"id\":2}Content-Length: 157"} Shutting down server.

The text in the editor does have colors, though, so I assume the language server is running now.

[snej]

Roc version is "roc nightly pre-release, built from commit dd9a6ff on Sat May 11 09:12:29 UTC 2024”

VS Code is Version: 1.85.0

[Anton-4]

Hi @snej,
Did you set Roc-lang › Language-server: Exe in the settings of the extension?
For me it is set to /Users/admin/Downloads/temp2/roc_nightly-macos_apple_silicon-2024-05-13-e5ea6dc4617/roc_language_server.
We mention it but it's easy to look over, I'll look into improving this.

[Anton-4]

Issues for improvements:
ivan-demchenko/roc-vscode-unofficial#29
ivan-demchenko/roc-vscode-unofficial#30

[Anton-4]

The text in the editor does have colors, though, so I assume the language server is running now.

That will work without the language server. If you introduce an error in to the code, e.g by changing Stdout.line to Stdout.lin and the error is underlined in red, the language server is working.

[snej]

Yes, I entered the path to the language server.

If you look closely at the error, it looks as though the language server is echoing some compiler status output (about downloading a package) to the HTTP response stream before the response headers are complete, and only afterwards sends the Content-Length header. Perhaps that output is being redirected to the wrong FD?

Client roc-lang: connection to server is erroring. Header must provide a Content-Length property. {"downloading \u001b[36mhttps":"//github.com/roc-lang/basic-cli/releases/download/0.10.0/vNe6s9hWzoTZtFmNkvEICPErI9ptji_ySjicO6CkucY.tar.br\u001b[0m\n into /Users/snej/.cache/roc/packages\n\nContent-Length: 38"} Shutting down server.

[Anton-4]

Hmm, what seems wrong to me is that {"downloading \u001b[36mhttps":"//github.com/roc-lang/basic-cli/releases/download/0.10.0/vNe6s9hWzoTZtFmNkvEICPErI9ptji_ySjicO6CkucY.tar.br\u001b[0m\n into /Users/snej/.cache/roc/packages\n\nContent-Length: 38"} is not the json we want. Content-Length is not a separate json field, it's just concatenated with the other value string.

Can you try updating to the latest vscode (1.89)? That version works on my mac.