Android Build

Android Build & Debug

Goal

Build, install, and debug Android apps entirely from the command line — no IDE required. Success = APK built, installed on device/emulator, and running without crashes. For release builds: signed APK ready for distribution.

Dependencies

• Tools: Bash (Gradle, ADB commands), Read (config files), Write (signing configs)
• Required CLI: ./gradlew (Gradle wrapper), adb (Android Debug Bridge), keytool (Java, for signing)
• Environment: ANDROID_HOME set, platform-tools in PATH (use /android-setup if not configured)

Context

• Read build.gradle.kts for existing build config, signing configs, and product flavors before running any build
• Check local.properties for SDK path and verify ANDROID_HOME is set
• Detect connected devices with adb devices before install or debug steps
• If environment is not configured, stop and suggest: "Run /skill-store install android-setup then /android-setup first"

Process

Step 1: Determine Target Action

If $ARGUMENTS is provided, route directly to the matching command section below (build, install, debug, sign, release). If no argument is given, ask the user: "What would you like to do? Options: build, install, debug, sign, release."

Step 2: Verify Environment

adb version
./gradlew --version

Confirm ANDROID_HOME is set and Gradle wrapper exists. If either fails, stop and guide setup.

CHECKPOINT: If environment checks fail, present the specific error and ask: "Your environment needs configuration. Should I walk you through fixing it, or would you like to run /android-setup first?"

Step 3: Execute Command

Run the appropriate command section based on the user's target action:

Build

./gradlew clean assembleDebug

Report: APK location (app/build/outputs/apk/debug/app-debug.apk), file size, build time.

CHECKPOINT: Show build result (success or failure). If failed, display the error and ask: "Build failed. Want me to diagnose this error?"

Install

1. Check for connected device:

adb devices

2. If no device is listed, guide USB debugging setup or emulator launch before continuing.
3. Install the APK:

adb install -r app/build/outputs/apk/debug/app-debug.apk

4. Launch the app:

adb shell am start -n com.package.name/.MainActivity

Debug

1. Start filtered logcat:

adb logcat -s "AppTag:V" "AndroidRuntime:E" "System.err:W" | head -200

2. Analyze common crash patterns:
   • FATAL EXCEPTION — read stack trace, identify the crashing line
   • ANR — main thread blocked; check for network or DB calls on main thread
   • ClassNotFoundException — ProGuard stripping; check rules
3. Collect device diagnostics:

adb shell getprop ro.build.version.sdk    # API level
adb shell dumpsys meminfo com.package.name # Memory usage

Sign

1. Read existing build.gradle.kts signing config to avoid duplicating keystore setup.
2. Present proposed keystore details to user.

CHECKPOINT: Confirm keystore details with user before generating. Ask: "I'll generate a keystore with these parameters. Confirm before I proceed — this is a security-critical operation."

3. Generate a self-signed release keystore (if none exists):

keytool -genkey -v -keystore release.keystore \
  -alias release -keyalg RSA -keysize 2048 -validity 10000

4. Configure signing in build.gradle.kts using environment variables — NEVER hardcode passwords:

signingConfigs {
    create("release") {
        storeFile = file("release.keystore")
        storePassword = System.getenv("KEYSTORE_PASSWORD")
        keyAlias = "release"
        keyPassword = System.getenv("KEY_PASSWORD")
    }
}

Note: release.keystore must be added to .gitignore.

Release

1. Run full test suite first:

./gradlew testReleaseUnitTest

2. Build signed release APK:

./gradlew assembleRelease

3. Verify APK signing:

apksigner verify --verbose app/build/outputs/apk/release/app-release.apk

CHECKPOINT: Present release APK path, file size, and signing verification output. Ask: "Release APK is ready. Confirm this looks correct before distribution."

Step 4: Report Results

Summarize what was done: command run, outcome, file paths produced, and any warnings.

Output

• Build: APK file path and size reported in terminal
• Install: Confirmation of successful installation and app launch
• Debug: Filtered logcat output with annotated crash analysis
• Sign: release.keystore file + updated signing config in build.gradle.kts
• Release: Signed APK at app/build/outputs/apk/release/app-release.apk, verified and ready for distribution

Common Build Errors