Rust Glancer

Rust Glancer for Zed

This extension connects Zed's built-in Rust language support to rust-glancer lsp. It uses an explicitly configured executable or one installed on PATH when available. Otherwise, the extension downloads its pinned Rust Glancer release and keeps it in Zed's extension work directory.

Managed installation is available for:

• macOS on Apple Silicon and Intel
• Linux with glibc 2.28 or newer on AArch64 and x86-64
• Windows on x86-64

Other platforms can still use the extension by configuring a compatible rust-glancer executable explicitly.

Development

Build the language server first:

cargo build --release -p rust-glancer

In Zed, run zed: extensions, choose Install Dev Extension, and select the editors/zed directory from this repository.

For a deterministic local setup, add the following project settings and replace the binary path with the path to this checkout:

{
  "languages": {
    "Rust": {
      "language_servers": ["rust-glancer", "!rust-analyzer"]
    }
  },
  "lsp": {
    "rust-glancer": {
      "binary": {
        "path": "/absolute/path/to/rust-glancer/target/release/rust-glancer",
        "arguments": ["lsp"]
      }
    }
  }
}

The extension uses ["lsp"] when binary.arguments is omitted. If arguments are configured, they replace that default and must retain the lsp subcommand. When binary.path is omitted, the extension looks for rust-glancer on the project's PATH and then falls back to its managed binary. Managed downloads are versioned, so restarting Zed can use an already installed server without network access. A new extension release pins a new server release instead of following the latest GitHub release automatically.

Rust Glancer applies its server-side configuration defaults when no initialization options are provided. Overrides use Zed's standard initialization_options object:

{
  "lsp": {
    "rust-glancer": {
      "initialization_options": {
        "cfg": {
          "test": true,
          "atoms": []
        },
        "diagnostics": {
          "onSave": true,
          "command": "check",
          "cargoArguments": ["--workspace"]
        }
      }
    }
  }
}

See the project configuration guide at docs/src/usage/CONFIGURE.md for the full set of initialization options.

To enable server logs, set an environment override on the language-server binary:

{
  "lsp": {
    "rust-glancer": {
      "binary": {
        "env": {
          "RUST_GLANCER_LOG": "rg_lsp_server=debug,rg_lsp_engine=debug"
        }
      }
    }
  }
}

Use Zed's dev: open language server logs, editor: restart language server, and editor: stop language server actions while troubleshooting.

Building the extension

Zed compiles development extensions automatically. To check the WebAssembly build directly:

rustup target add wasm32-wasip2
cargo build -p rust-glancer-zed --target wasm32-wasip2