How to debug LanguageServer (in VSCode) problems?

I’m using Julia 1.4.2 with VSCode Insiders and the Julia Insiders extension v0.17.5 on a Mac with Catalina.

Ever since extension v0.17, the LanguageServer hangs. I’m in a directory with empty Project.toml and Manifest.toml files (though I get a similar hang in an environment with dependencies - just takes longer to get to the hang). I can see the julia process that runs the LanguageServer. It runs for about 18 seconds and then never takes more CPU time. The “Starting Julia Language Server” in the VSCode status bar never changes. IntelliSense and Julia help do not work in the editor.

Here’s what I see in the Output window …

[ Info: Starting the Julia Language Server
[ Info: Symbol server store is at '/Users/lyon/Library/Application Support/Code - Insiders/User/globalStorage/julialang.language-julia-insider/symbolstorev2'.
[ Info: Received new data from Julia Symbol Server.

If I quit VSCode, the Julia Language Server process persists, never taking more CPU time. I have to manually kill the process.

Is this a known problem? Is there a way to debug this? It’s really frustrating to lose the ability to edit Julia code effectively (note that I’ve tried the regular Julia extension - which today is at the same version as the insiders - and I have the same problem).

Thanks for any help/advice! – Adam

Have people moved on to the Julia 1.5 beta or rc? Does anyone have success with the LanguageServer with that version?

There should be no issues related to those julia versions in particular. Could you kill the julia language server process while vscode remains open and report back any messages that are subsequently printed to the output pane? (either here or open an issue at

1 Like

Thanks Zac! I opened .

Another quick update - the LanguageServer seems to work for regular VSCode. It fails for VSCode-insiders. See the link to the issue above.