How do we update the version of clangd that comes bundled with Zed?

[jedrichards]

Looking at my system the version of clangd that comes with Zed is ancient:

/Users/{USER}/Library/Application\ Support/Zed/languages/clangd/clangd_16.0.2/bin/clangd --version
clangd version 16.0.2 (https://github.com/llvm/llvm-project 18ddebe1a1a9bde349441631365f0472e9693520)
Features: mac+grpc+xpc
Platform: x86_64-apple-darwin24.5.0

The latest version is 20.1.8.

Is there anyway to update this? I know I can adjust the path to the binary in the lsp settings, but a built in way might be better. For example in VS Code there's a clangd: check for language server update command.

At the moment I'm resorting to configuring Zed to use VS Code's clangd binary 😅

{
  "lsp": {
    "clangd": {
      "binary": {
        "path": "/Users/{USER}/Library/Application Support/Code/User/globalStorage/llvm-vs-code-extensions.vscode-clangd/install/20.1.8/clangd_20.1.8/bin/clangd",
      }
    }
  }
}

I would rather not resort to brew install llvm to get a recent clangd, since I don't want to clobber my OS too badly. Having a pre-built bin in a folder somewhere, is more appealing.

[SomeoneToIgnore]

The

zed/crates/languages/src/c.rs

Lines 40 to 63 in 42b2b65

	async fn fetch_latest_server_version(
	&self,
	delegate: &dyn LspAdapterDelegate,
	) -> Result<Box<dyn 'static + Send + Any>> {
	let release =
	latest_github_release("clangd/clangd", true, false, delegate.http_client()).await?;
	let os_suffix = match consts::OS {
	"macos" => "mac",
	"linux" => "linux",
	"windows" => "windows",
	other => bail!("Running on unsupported os: {other}"),
	};
	let asset_name = format!("clangd-{}-{}.zip", os_suffix, release.tag_name);
	let asset = release
	.assets
	.iter()
	.find(|asset| asset.name == asset_name)
	.with_context(|| format!("no asset found matching {asset_name:?}"))?;
	let version = GitHubLspBinaryVersion {
	name: release.tag_name,
	url: asset.browser_download_url.clone(),
	};
	Ok(Box::new(version) as Box<_>)
	}

code is supposed to handle latest version normally by looking at the latest stable release in https://github.com/clangd/clangd/releases

I've had no predownloaded clang and when I've opened a *.c file, the clangd_20.1.8 was downloaded fine.

Could it be that the update path is not working properly?
If you try the regular lsp.clangd.binary settings, what do the logs contain?

[jedrichards]

Hmm, the plot thickens. If I remove my lsp.clangd.binary settings, and check the Server Info lsp log, I see:

Binary: LanguageServerBinary {
    path: "/usr/bin/clangd",
    arguments: [],
    ...etc

So it seems like it's using my system clangd in that case, not even the old one installed in Zed's Application Support folder.

I'm not sure that update path you mentioned is working anyway for me, because having opened and closed a bunch of C++ and C files, Zed's Application Support folder for clangd still just looks like

[SomeoneToIgnore]

What about regular Zed logs, anything clang-related there?

[jedrichards]

I see this:

2025-07-17T11:53:55+01:00 INFO  [language] found user-installed language server for clangd. path: "/usr/bin/clangd", arguments: []

Nothing else relevant, or any logs about trying to update.

So maybe it sees there's already a clangd on the path, and doesn't bother to update?

The Apple clangd will be on most native dev's path, since it comes with XCode. But it's very rarely the one you'd want to use on a project (it's also old).

I would say the default behaviour of the extension should be to always default to latest binary of clangd it can download 🤔

[SomeoneToIgnore]

"binary": {
  "ignore_system_version": true
}

is presumably supposed to help with this.

Currently, we do not want to have a default that always downloads things, as it currently does not work well offline and is not something that other groups of people want.
Some time later that is supposed to be changed, after a better downloads/permissions and binary management story is implemented.

[jedrichards]

Oh right, well it seems that ignore_system_version is exactly what I need then 😌

Thanks!