What causes "Gradle build failed!" in quasarframework/quasar?

Re-run with the full Gradle output visible (or run `./gradlew assembleDebug` in /android directly) to see the real root-cause error above the warning.

quasarframework/quasar · error

Gradle build failed!

Error message

Gradle build failed!

What it means

During a Capacitor Android build, #buildAndroid shells out to the Gradle wrapper (gradlew assembleDebug/assembleRelease, plus any extra argv) inside <app>/android. The callback fires when Gradle exits non-zero; Quasar warns 'Gradle build failed!' and suggests building from the IDE with --ide.

Source

Thrown at app-vite/lib/modes/capacitor/capacitor-builder.js:141

    const buildPath = this.ctx.appPaths.resolve.capacitor(
      'android/app/build/outputs'
    )

    // Remove old build output
    fse.removeSync(buildPath)

    log('Building Android app...')

    await spawnSync(
      `./gradlew${process.platform === 'win32' ? '.bat' : ''}`,
      [
        `assemble${this.quasarConf.metaConf.debugging ? 'Debug' : 'Release'}`,
        ...this.argv._
      ],
      { cwd: this.ctx.appPaths.resolve.capacitor('android') },
      () => {
        warn()
        warn('Gradle build failed!')
        warn(
          'As an alternative, you can use the "--ide" param and build from the IDE.'
        )
        warn()
      }
    )

    fse.copySync(buildPath, this.#packagedDir)
  }
}

View on GitHub (pinned to 4841521b5f)

Solutions

Re-run with the full Gradle output visible (or run `./gradlew assembleDebug` in <app>/android directly) to see the real root-cause error above the warning.
Verify JAVA_HOME points to a compatible JDK (17 for recent Android Gradle Plugin) and Android SDK platforms/build-tools are installed.
Clean Gradle state: `cd src-capacitor/android && ./gradlew clean` and delete build/.gradle caches if corrupted.
If you only need to open/edit natively, use `quasar dev -m capacitor -T android --ide` or build from Android Studio as the warning suggests.
Ensure Capacitor android platform is synced (`npx cap sync android`) and AGP/Gradle versions match the installed Capacitor version.

Example fix

// before (shell)
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk
quasar build -m capacitor -T android
// after
export JAVA_HOME=/usr/lib/jvm/java-17-openjdk
cd src-capacitor/android && ./gradlew clean
quasar build -m capacitor -T android

Defensive patterns

Strategy: try-catch

Validate before calling

// pre-flight checks before `quasar build -m capacitor -T android`
const { execSync } = require('child_process')
console.log('JAVA_HOME =', process.env.JAVA_HOME || '(unset)')
execSync('java -version', { stdio: 'inherit' })            // must be JDK 17+ for recent AGP
execSync('sdkmanager --list | head', { stdio: 'inherit' }) // Android SDK reachable
execSync('cd src-capacitor/android && ./gradlew --version', { stdio: 'inherit' })

Try / catch

// wrap the CLI invocation
try {
  execSync('npx quasar build -m capacitor -T android', { stdio: 'inherit' })
} catch (err) {
  console.error('Gradle build failed; inspect the gradlew output above, then retry with:\n  cd src-capacitor/android && ./gradlew clean\n  cd ../.. && quasar build -m capacitor -T android --ide')
  process.exit(err.status || 1)
}

Prevention

Pin JAVA_HOME to JDK 17 for current Android Gradle Plugin versions.
Run `npx cap sync android` after capacitor config or plugin changes.
Keep AGP/Gradle wrapper versions aligned with the Capacitor version in use.
Run `./gradlew clean` when builds fail after partial/interrupted runs.
Read the gradlew stderr above the warning — Quasar only reports the failure, not the cause.

When it happens

Trigger: Running `quasar build -m capacitor -T android` (or dev) and the spawned `./gradlew assembleDebug|Release` process returns an error exit code; the warning callback of runGradle is invoked.

Common situations: Missing/incorrect ANDROID SDK or JAVA_HOME (JDK 17 required for recent AGP); compile errors in custom Java/Kotlin plugin code; corrupted Gradle cache or lock files; insufficient memory; mismatched AGP/Gradle versions after upgrading Capacitor; signing config errors in release builds.

Related errors

AI-assisted analysis of quasarframework/quasar@4841521b5f (2026-08-30). Data as JSON: /api/errors/d24efe169e6a1ae3. Report an issue: GitHub.