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Android SDK Issues

"ANDROID_HOME not set"​

JetStart and Gradle cannot find the Android SDK.

Fix — set the environment variable permanently:

Windows:

  1. Search "Edit the system environment variables" → Environment Variables
  2. Under User variables, click New:
    • Variable name: ANDROID_HOME
    • Variable value: C:\Android (or wherever your SDK is)
  3. Also add to the Path variable:
    • %ANDROID_HOME%\platform-tools
    • %ANDROID_HOME%\cmdline-tools\latest\bin
  4. Restart your terminal

macOS/Linux — add to ~/.zshrc or ~/.bashrc:

export ANDROID_HOME=$HOME/Android/Sdk
export PATH=$PATH:$ANDROID_HOME/cmdline-tools/latest/bin
export PATH=$PATH:$ANDROID_HOME/platform-tools

Then reload:

source ~/.zshrc   # or source ~/.bashrc

Common SDK locations:

PlatformDefault path
WindowsC:\Users\<User>\AppData\Local\Android\Sdk
Windows (manual install)C:\Android
macOS~/Library/Android/sdk
Linux~/Android/Sdk

"d8 not found" or "build-tools not installed"​

d8 is part of Android build-tools. JetStart needs it for the hot reload DEX pipeline.

Fix:

sdkmanager "build-tools;34.0.0"

Verify it was installed:

ls $ANDROID_HOME/build-tools/
# Should show at least one version folder, e.g. 34.0.0

"android.jar not found" / classpath build fails​

The Kotlin compiler needs android.jar from the SDK platforms directory.

Fix:

sdkmanager "platforms;android-34"

Verify:

ls $ANDROID_HOME/platforms/
# Should show: android-34 (or another version)

Gradle Build Fails with "License not accepted"​

Failed to install the following Android SDK packages as some licenses have not been accepted.

Fix:

sdkmanager --licenses
# Press 'y' to accept each license

Or non-interactively:

yes | sdkmanager --licenses

"Gradle build failed" — Java version mismatch​

JetStart requires JDK 17. Using JDK 8, 11, or 21 with certain Gradle/AGP versions causes incompatibilities.

Check your Java version:

java -version
# Should show: openjdk version "17.x.x"

Install JDK 17:

# macOS (Homebrew)
brew install --cask temurin@17

# Linux (Debian/Ubuntu)
sudo apt install openjdk-17-jdk

# Linux (SDKMAN)
sdk install java 17.0.9-tem

Download for Windows: Eclipse Temurin 17

Set JAVA_HOME:

export JAVA_HOME=/path/to/jdk17   # macOS/Linux
set JAVA_HOME=C:\Program Files\Eclipse Adoptium\jdk-17.0.9.9-hotspot   # Windows

SDK Manager Not Found​

'sdkmanager' is not recognized as an internal or external command

Cause: cmdline-tools is not installed or not in PATH.

Fix — install command-line tools:

  1. Download from developer.android.com/studio#command-tools
  2. Extract to $ANDROID_HOME/cmdline-tools/latest/

Directory structure should be:

$ANDROID_HOME/
  cmdline-tools/
    latest/
      bin/
        sdkmanager
        avdmanager
  1. Add to PATH:
export PATH=$PATH:$ANDROID_HOME/cmdline-tools/latest/bin

Emulator Hardware Acceleration Not Available​

Your CPU does not support required features (VT-x or AMD-V)

Windows — enable in BIOS:

  1. Restart and enter BIOS (usually F2, Del, or F12 during boot)
  2. Find "Intel Virtualization Technology" (VT-x) or "AMD-V"
  3. Enable it and save

Windows — HAXM vs WHPX:

  • If Hyper-V is enabled, HAXM will not work. Use WHPX instead: 
    Enable-WindowsOptionalFeature -Online -FeatureName HypervisorPlatform

Linux — enable KVM:

# Install KVM
sudo apt install qemu-kvm

# Add current user to kvm group
sudo usermod -aG kvm $USER

# Log out and back in, then verify
ls -la /dev/kvm

ADB Device Not Detected​

adb: no devices/emulators found

For physical devices:

  1. Enable Developer Options: Settings → About phone → tap "Build number" 7 times
  2. Enable USB Debugging: Developer Options → USB Debugging
  3. Connect via USB and accept the "Allow USB debugging" prompt on the device
  4. Verify: adb devices should list the device

For wireless ADB (JetStart --emulator): ADB wireless connection is handled automatically by JetStart. If it fails:

# Reset ADB
adb kill-server
adb start-server

# Manually connect
adb connect <device-ip>:5555

Running jetstart install-audit​

The fastest way to diagnose Android SDK issues is to run the built-in audit:

jetstart install-audit

This checks:

  • Node.js version
  • npm version
  • Java/JDK version and JAVA_HOME
  • Gradle version
  • ANDROID_HOME presence
  • Android SDK components (platform-tools, build-tools, platforms)

Use --json for machine-readable output suitable for CI/CD:

jetstart install-audit --json