Tauri Errors Build

tauri-errors-build

Quick Diagnosis

When a Tauri 2 build fails, identify the phase first:

Build Pipeline Phases:
1. Frontend build   (beforeBuildCommand)  --> JS/TS errors
2. Cargo compile    (rustc)               --> Rust compilation errors
3. Bundler          (NSIS/WiX/DMG/deb)    --> Platform packaging errors
4. Code signing     (codesign/signtool)   --> Signing/notarization errors

ALWAYS read the FULL error output. The root cause is often buried above the final error message.

NEVER skip cargo clean when troubleshooting persistent compilation errors -- stale build artifacts cause phantom failures.

Error Lookup Table: Cargo Compilation

ERR-B001: Command function visibility in lib.rs

Error: error[E0255]: the name X is defined multiple times or cryptic macro expansion errors.

Cause: Command functions defined directly in src-tauri/src/lib.rs are marked pub.

Fix: ALWAYS remove pub from command functions in lib.rs. Commands in separate modules MUST be pub.

// WRONG -- in lib.rs
#[tauri::command]
pub fn greet(name: String) -> String { ... }

// CORRECT -- in lib.rs
#[tauri::command]
fn greet(name: String) -> String { ... }

// CORRECT -- in src-tauri/src/commands.rs (separate module)
#[tauri::command]
pub fn greet(name: String) -> String { ... }

ERR-B002: Missing Serialize on error type

Error: the trait bound MyError: Serialize is not satisfied

Cause: Command return type Result<T, E> requires E to implement serde::Serialize.

Fix: ALWAYS implement Serialize manually for error enums that use thiserror:

#[derive(Debug, thiserror::Error)]
enum AppError {
    #[error(transparent)]
    Io(#[from] std::io::Error),
    #[error("not found: {0}")]
    NotFound(String),
}

impl serde::Serialize for AppError {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where S: serde::ser::Serializer {
        serializer.serialize_str(self.to_string().as_ref())
    }
}

ERR-B003: Borrowed references in async commands

Error: implementation of FnOnce is not general enough or lifetime errors in async command signatures.

Cause: Async commands cannot use &str directly due to spawning on the tokio runtime.

Fix: Use owned types (String) or wrap return in Result:

// WRONG
#[tauri::command]
async fn process(value: &str) -> String { value.to_uppercase() }

// CORRECT -- option 1: owned type
#[tauri::command]
async fn process(value: String) -> String { value.to_uppercase() }

// CORRECT -- option 2: wrap in Result
#[tauri::command]
async fn process(value: &str) -> Result<String, ()> { Ok(value.to_uppercase()) }

ERR-B004: Multiple invoke_handler calls

Error: Commands silently not working -- no compilation error.

Cause: Only the LAST .invoke_handler() call on Builder takes effect. Multiple calls do NOT merge.

Fix: ALWAYS use a single generate_handler![] with all commands:

// WRONG -- only cmd2 works
tauri::Builder::default()
    .invoke_handler(tauri::generate_handler![cmd1])
    .invoke_handler(tauri::generate_handler![cmd2])

// CORRECT
tauri::Builder::default()
    .invoke_handler(tauri::generate_handler![cmd1, cmd2])

ERR-B005: Mobile crate-type missing

Error: cannot produce cdylib for app_lib or linking errors on tauri android build / tauri ios build.

Cause: Cargo.toml missing required crate types for mobile targets.

Fix: ALWAYS include all three crate types when targeting mobile:

[lib]
name = "app_lib"
crate-type = ["staticlib", "cdylib", "rlib"]

ERR-B006: Missing mobile entry point

Error: App crashes immediately on mobile, or tauri android build / tauri ios build fails with missing symbol errors.

Cause: Missing #[cfg_attr(mobile, tauri::mobile_entry_point)] macro or incorrect project structure.

Fix: ALWAYS split into lib.rs + main.rs for mobile support:

// src-tauri/src/lib.rs
#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
    tauri::Builder::default()
        .invoke_handler(tauri::generate_handler![])
        .run(tauri::generate_context!())
        .expect("error while running tauri application");
}

// src-tauri/src/main.rs
fn main() {
    app_lib::run();
}

Error Lookup Table: Linux Dependencies

ERR-B010: Missing webkit2gtk

Error: Package webkit2gtk-4.1 was not found or error: could not find system library 'webkit2gtk-4.1'

Fix: Install required system dependencies:

# Ubuntu/Debian
sudo apt-get update
sudo apt-get install -y \
    libwebkit2gtk-4.1-dev \
    libappindicator3-dev \
    librsvg2-dev \
    patchelf

# Fedora
sudo dnf install webkit2gtk4.1-devel libappindicator-gtk3-devel librsvg2-devel

# Arch
sudo pacman -S webkit2gtk-4.1 libappindicator-gtk3 librsvg

NEVER install libwebkit2gtk-4.0-dev -- Tauri 2 requires the 4.1 variant.

ERR-B011: Missing build tools

Error: linker cc not found or failed to run custom build command

Fix: Install base build tools:

sudo apt-get install -y build-essential curl wget file libssl-dev libgtk-3-dev \
    libayatana-appindicator3-dev

Error Lookup Table: Bundler Errors

ERR-B020: NSIS installer failure (Windows)

Error: NSIS Error or MakeNSIS exited with error

Common causes and fixes:

1. Path too long -- shorten productName or move project closer to drive root
2. Missing NSIS -- install via choco install nsis or winget install NSIS.NSIS
3. Icon format wrong -- NSIS requires .ico files with specific sizes

ERR-B021: WiX/MSI failure (Windows)

Error: candle.exe exited with error or light.exe exited with error

Fix: Install WiX Toolset v3: dotnet tool install --global wix

ERR-B022: DMG creation failure (macOS)

Error: hdiutil: create failed or DMG size errors

Common causes: Disk space insufficient, or icon file path incorrect in tauri.conf.json.

ERR-B023: AppImage failure (Linux)

Error: AppImage bundling failed or missing appimagetool

Fix: Ensure FUSE is available. On Ubuntu 22.04+:

sudo apt-get install -y libfuse2

ERR-B024: WebView2 bootstrapper (Windows)

Error: Failed to download WebView2 bootstrapper

Fix: Configure offline installation in tauri.conf.json:

{
  "bundle": {
    "windows": {
      "webviewInstallMode": "offlineInstaller"
    }
  }
}

Error Lookup Table: Code Signing

ERR-B030: macOS unsigned app blocked

Error: "MyApp" is damaged and can't be opened or Gatekeeper rejection.

Fix: At minimum use ad-hoc signing for testing:

{
  "bundle": {
    "macOS": {
      "signingIdentity": "-"
    }
  }
}

For distribution, ALWAYS use a proper Developer ID certificate.

ERR-B031: macOS notarization failure

Error: The signature of the binary is invalid or notarytool errors.

Checklist:

1. Hardened runtime enabled: "hardenedRuntime": true
2. Signing identity correct: "Developer ID Application: Name (TEAMID)"
3. Environment variables set: APPLE_API_ISSUER, APPLE_API_KEY, APPLE_API_KEY_PATH
4. Certificate not expired

ERR-B032: Windows Authenticode failure

Error: SignTool Error or certificate thumbprint not found

Checklist:

1. Certificate installed in current user store
2. Thumbprint matches: "certificateThumbprint": "A1B2..."
3. Timestamp URL reachable: "timestampUrl": "http://timestamp.comodoca.com"

Error Lookup Table: CI/CD

ERR-B040: GitHub Actions Linux build fails

Error: Various dependency errors in CI.

Fix: ALWAYS include the Linux dependency installation step:

- name: Install Linux dependencies
  if: runner.os == 'Linux'
  run: |
    sudo apt-get update
    sudo apt-get install -y libwebkit2gtk-4.1-dev libappindicator3-dev librsvg2-dev

ERR-B041: GitHub token permissions

Error: Resource not accessible by integration or 403 on release creation.

Fix: Set permissions in workflow:

permissions:
  contents: write

And ensure repository Settings > Actions > General > Workflow permissions is set to "Read and write."

ERR-B042: Updater artifact build fails

Error: TAURI_SIGNING_PRIVATE_KEY must be set

Cause: "createUpdaterArtifacts": true in config but no signing key.

Fix: Either set the environment variable in CI secrets, or set "createUpdaterArtifacts": false if not using auto-updater.

ERR-B043: Cross-compilation target missing

Error: error[E0463]: can't find crate for std when building for a different architecture.

Fix: Install the target toolchain:

# macOS universal binary
rustup target add aarch64-apple-darwin x86_64-apple-darwin

# Android
rustup target add aarch64-linux-android armv7-linux-androideabi i686-linux-android x86_64-linux-android

# iOS
rustup target add aarch64-apple-ios x86_64-apple-ios aarch64-apple-ios-sim

Diagnostic Decision Tree

Build failed?
|
+-- Is it a Rust compilation error?
|   +-- Type mismatch in command? --> Check ERR-B001, ERR-B002, ERR-B003
|   +-- Symbol/linking error? --> Check ERR-B005, ERR-B006, ERR-B043
|   +-- Commands not found at runtime? --> Check ERR-B004
|
+-- Is it a system dependency error?
|   +-- Linux? --> Check ERR-B010, ERR-B011
|   +-- Windows WebView2? --> Check ERR-B024
|
+-- Is it a bundler error?
|   +-- Windows NSIS/WiX? --> Check ERR-B020, ERR-B021
|   +-- macOS DMG? --> Check ERR-B022
|   +-- Linux AppImage? --> Check ERR-B023
|
+-- Is it a code signing error?
|   +-- macOS? --> Check ERR-B030, ERR-B031
|   +-- Windows? --> Check ERR-B032
|
+-- Is it a CI/CD error?
    +-- Linux deps? --> Check ERR-B040
    +-- Permissions? --> Check ERR-B041
    +-- Updater keys? --> Check ERR-B042
    +-- Cross-compile? --> Check ERR-B043

General Troubleshooting Steps

1. ALWAYS run cargo clean in src-tauri/ before retrying
2. ALWAYS check tauri info output for environment diagnostics
3. ALWAYS verify tauri.conf.json has valid JSON (use schema validation)
4. NEVER ignore warnings -- they often become errors in release builds
5. NEVER assume a build works on all platforms because it works on one

Reference Links

• references/methods.md -- Build commands, environment variables, configuration keys
• references/examples.md -- Working build configurations and CI/CD templates
• references/anti-patterns.md -- Build configuration mistakes with fixes

Official Sources

• https://v2.tauri.app/start/prerequisites/
• https://v2.tauri.app/distribute/
• https://v2.tauri.app/develop/debug/