`tauri dev` is incredibly slow

[seaglade]

Describe the bug

When running tauri dev the app takes minutes to launch, and a single change to a file forces it to start over, seemingly from scratch. This happens when running yarn tauri dev in the unchanged result of yarn create tauri-app. Around 300 rust libraries seem to be getting compiled every time a change is made.

Reproduction

yarn create tauri-app # Fill out the form and let it create the project
cd <app-directory>
yarn
yarn tauri dev

Expected behavior

Interface loads quickly and refreshes quickly when files are changed.

Full tauri info output

[✔] Environment
    - OS: Windows 10.0.22631 X64
    ✔ WebView2: 121.0.2277.128
    ✔ MSVC: Visual Studio Community 2022
    ✔ rustc: 1.74.1 (a28077b28 2023-12-04)
    ✔ cargo: 1.74.1 (ecb9851af 2023-10-18)
    ✔ rustup: 1.26.0 (5af9b9484 2023-04-05)
    ✔ Rust toolchain: stable-x86_64-pc-windows-msvc (default)
    - node: 21.6.1
    - pnpm: 8.15.3
    - yarn: 1.22.19
    - npm: 10.2.4

[-] Packages
    - tauri [RUST]: 1.6.0
    - tauri-build [RUST]: 1.5.1
    - wry [RUST]: 0.24.7
    - tao [RUST]: 0.16.7
    - @tauri-apps/api [NPM]: 1.5.3
    - @tauri-apps/cli [NPM]: 1.5.10

[-] App
    - build-type: bundle
    - CSP: unset
    - distDir: ../dist
    - devPath: http://localhost:1420/
    - framework: React
    - bundler: Vite

Stack trace

No response

Additional context

No response

[seaglade]

Huh, if the change is made to the UI the interface reloads instantly. It's only backend changes that take so long. That makes a bit more sense but is still problematic.

[seaglade]

Running tauri build and then tauri dev seems to have fixed the issue. I'm guessing the dev command does something differently that causes it to rebuild everything every single time. Regardless, I hope that this can be documented somewhere and/or fixed.

[amrbashir]

This is something related to Rust and its incremental compilation, it shouldn't recompile your dependencies unless necessary. Anyways, there is nothing we can do since this seems like a Rust issue.

[kon72]

If you are using rust-analyzer on VS Code, try using separate target directory for rust-analyzer and tauri.

.vscode/settings.json:

{
  "rust-analyzer.server.extraEnv": {
    "CARGO_TARGET_DIR": "${workspaceFolder}/src-tauri/target/analyzer"
  },
  "rust-analyzer.cargo.targetDir": "${workspaceFolder}/src-tauri/target/analyzer"
}

ref: rust-lang/rust-analyzer#4616

[rxliuli]

I encountered the same problem. On the M2 Max, every time I modify the Rust code, it blocks and compiles for more than 30 seconds. I don't know why the created template project has issues, but obviously, this is problematic.

Kapture.2025-04-25.at.15.42.38.mp4

[FabianLars]

@rxliuli yours sounds more like this #11577 (has a workaround inside)

[rxliuli]

@rxliuli yours sounds more like this #11577 (has a workaround inside)

Yes, I know this temporary workaround. But I don't understand why it wasn't done correctly in the template project directly, and instead you have to manually modify the configuration to fix such an obvious problem.