App Debugging

With all the moving pieces in Tauri, you may run into a problem that requires debugging. There are a handful of locations where error details are printed, and Tauri includes some tools to make the debugging process easier.

Rust Console

When you run a Tauri app in development mode you will have a Rust console available. This is in the terminal where you ran e.g. tauri dev. You can use the following code to print something to that console from within a Rust file:

println!("Message from Rust: {}", msg);

Sometimes you may have an error in your Rust code, and the Rust compiler can give you lots of information. If, for example, tauri dev crashes, you can rerun it like this on Linux and macOS:

RUST_DEBUG=1 tauri dev

or like this on MS Windows:

set RUST_DEBUG=1
tauri dev

This will give you a granular stack trace. Generally speaking, the Rust compiler will help you by giving you detailed information about the issue, such as:

error[E0425]: cannot find value `sun` in this scope
  --> src/main.rs:11:5
   |
11 |     sun += i.to_string().parse::<u64>().unwrap();
   |     ^^^ help: a local variable with a similar name exists: `sum`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0425`.

Webview JS Console

Linux & macOS

Right click in the webview, and choose Inspect Element. This will open up a web-inspector similar to the Chrome or Firefox dev tools you are used to.

Windows

If you enable the Edge backend (tauri = { version = "*", features = ["edge"] } in src-tauri/Cargo.toml) you can use the standalone Edge DevTools app.

This enables you to connect the dev tools to your Rust-backed web view as if it were a normal Edge window. (Thanks to @dkaste for providing the solution in this issue).

If you are using MSHTML, then you will probably have to use firebug:

<script
  type="text/javascript"
  src="https://getfirebug.com/firebug-lite.js"
></script>

See this thread for more information.

Create a Debug Build

There are cases where you might need to inspect the JS console in the final bundle, so Tauri provides a simple command to create a debugging bundle:

yarn tauri build --debug

Like the normal build and dev processes, the first time you run this it will take more time than subsequent runs. The final bundled app will be placed in src-tauri/target/debug/bundle. That app will ship with the development console enabled.

Run Your App From the Terminal

You can also run a built app from the terminal, which will also give you the Rust compiler notes (in case of errors) or your println messages. Just find the file src-tauri/target/(release or debug)/app and either double click it (but be warned, the terminal will close on errors) or just run it in directly in your console.