npx react-native run-android Failing in macOS

1. I Had Setup Android Studio installed in Mac
2. I had installed ADB Nexus 6p (R and Android Pie)
3. Tried Manually Running Android Emulator - Works Perfect

AVD Manager:

Nexus 6p with Android R and Android Pie

Installed SDK:

SDK Platforms

bash_profile or bashrc

Command Used: nano .bash_profile

export ANDROID_HOME=/Users/user/Library/Android/sdk
export PATH=${PATH}:/Users/user/Library/Android/sdk/tools
export PATH=${PATH}:/Users/user/Library/Android/sdk/platform-tools
export PATH=$PATH:$ANDROID_HOME/emulator
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/tools/bin
export PATH=$PATH:$ANDROID_HOME/platform-tools

Command used: npx @react-native-community/cli doctor

user@Devs-Mac MyReactApp % npx @react-native-community/cli doctor
Common
 ✓ Node.js
 ✓ yarn
 ✓ Watchman - Used for watching changes in the filesystem when in development mode

Android
 ✓ JDK
 ✖ ANDROID_HOME
 ✖ Android SDK - Required for building and installing your app on Android
   - Versions found: N/A
   - Version supported: 28.0.3

iOS
 ✓ Xcode - Required for building and installing your app on iOS
 ✓ CocoaPods - Required for installing iOS dependencies
 ✓ ios-deploy - Required for installing your app on a physical device with the CLI

Command used: npx react-native run-android

user@Devs-Mac MyReactApp % npx react-native run-android
info Running jetifier to migrate libraries to AndroidX. You can disable it using "--no-jetifier" flag.
Jetifier found 967 file(s) to forward-jetify. Using 8 workers...
info Starting JS server...
/bin/sh: adb: command not found
info Launching emulator...
error Failed to launch emulator. Reason: No emulators found as an output of `emulator -list-avds`.
warn Please launch an emulator manually or connect a device. Otherwise app may fail to launch.
info Installing the app...

FAILURE: Build failed with an exception.

* What went wrong:
Could not initialize class org.codehaus.groovy.runtime.InvokerHelper

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 748ms

error Failed to install the app. Make sure you have the Android development environment set up: https://reactnative.dev/docs/getting-started.html#android-development-environment. Run CLI with --verbose flag for more details.
Error: Command failed: ./gradlew app:installDebug -PreactNativeDevServerPort=8081

FAILURE: Build failed with an exception.

* What went wrong:
Could not initialize class org.codehaus.groovy.runtime.InvokerHelper

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 748ms

    at makeError (/Users/user/Desktop/sa/MyReactApp/node_modules/execa/index.js:174:9)
    at /Users/user/Desktop/sa/MyReactApp/node_modules/execa/index.js:278:16
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async runOnAllDevices (/Users/user/Desktop/sa/MyReactApp/node_modules/@react-native-community/cli-platform-android/build/commands/runAndroid/runOnAllDevices.js:94:5)
    at async Command.handleAction (/Users/user/Desktop/sa/MyReactApp/node_modules/@react-native-community/cli/build/index.js:186:9)

File local.properties inside android folder of React-native project

## This file must *NOT* be checked into Version Control Systems,
# as it contains information specific to your local configuration.
#
# Location of the SDK. This is only used by Gradle.
# For customization when using a Version Control System, please read the
# header note.
#Tue Apr 21 17:57:13 IST 2020
sdk.dir=/Users/user/Library/Android/sdk

Command: react-native info Environment Information

user@Devs-Mac MyReactApp % react-native info
info Fetching system and libraries information...
System:
    OS: macOS 10.15.4
    CPU: (8) x64 Intel(R) Core(TM) i7-3615QM CPU @ 2.30GHz
    Memory: 8.14 GB / 16.00 GB
    Shell: 5.7.1 - /bin/zsh
  Binaries:
    Node: 13.13.0 - /usr/local/bin/node
    Yarn: 1.22.4 - /usr/local/bin/yarn
    npm: 6.14.4 - /usr/local/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  Managers:
    CocoaPods: 1.9.1 - /usr/local/bin/pod
  SDKs:
    iOS SDK:
      Platforms: iOS 13.4, DriverKit 19.0, macOS 10.15, tvOS 13.4, watchOS 6.2
    Android SDK: Not Found
  IDEs:
    Android Studio: 3.6 AI-192.7142.36.36.6308749
    Xcode: 11.4/11E146 - /usr/bin/xcodebuild
  Languages:
    Java: 14.0.1 - /usr/bin/javac
    Python: 2.7.16 - /usr/bin/python
  npmPackages:
    @react-native-community/cli: Not Found
    react: 16.11.0 => 16.11.0 
    react-native: 0.62.2 => 0.62.2 
  npmGlobalPackages:
    *react-native*: Not Found

Even ran brew cask install android-sdk Just to make it work Logs Below

user@Devs-Mac ~ % brew cask install android-sdk
Updating Homebrew...
==> Caveats
You can control android sdk packages via the sdkmanager command.
You may want to add to your profile:

  'export ANDROID_SDK_ROOT="/usr/local/share/android-sdk"'

android-sdk requires Java 8. You can install it with:
  brew cask install homebrew/cask-versions/adoptopenjdk8

==> Downloading https://dl.google.com/android/repository/sdk-tools-darwin-4333796.zip
######################################################################## 100.0%
==> Verifying SHA-256 checksum for Cask 'android-sdk'.
==> Installing Cask android-sdk
==> Linking Binary 'android' to '/usr/local/bin/android'.
==> Linking Binary 'archquery' to '/usr/local/bin/archquery'.
==> Linking Binary 'avdmanager' to '/usr/local/bin/avdmanager'.
==> Linking Binary 'jobb' to '/usr/local/bin/jobb'.
==> Linking Binary 'lint' to '/usr/local/bin/lint'.
==> Linking Binary 'monkeyrunner' to '/usr/local/bin/monkeyrunner'.
==> Linking Binary 'screenshot2' to '/usr/local/bin/screenshot2'.
==> Linking Binary 'sdkmanager' to '/usr/local/bin/sdkmanager'.
==> Linking Binary 'uiautomatorviewer' to '/usr/local/bin/uiautomatorviewer'.
==> Linking Binary 'emulator' to '/usr/local/bin/emulator'.
==> Linking Binary 'emulator-check' to '/usr/local/bin/emulator-check'.
==> Linking Binary 'mksdcard' to '/usr/local/bin/mksdcard'.
==> Linking Binary 'monitor' to '/usr/local/bin/monitor'.
🍺  android-sdk was successfully installed!

Issue Still same

[sunguoxing0628]

@RockinGarg i hope it helps you

1、open a terminal 2、touch ~/.bash_profile 3、open ~/.bash_profile 4、write

export ANDROID_HOME=/Users/yourname/Library/Android/sdk
export PATH=$ANDROID_HOME/tools:$PATH
export PATH=$ANDROID_HOME/platform-tools:$PATH

5、source ~/.bash_profile(if it doesn’t work,next) 6、change "android": "react-native run-android" to "android": "source ~/.bash_profile&&react-native run-android", and run yarn android

[developius]

This is happening for me too. It was all working fine yesterday, I could run my RN app on both iOS and Android. Today however, I’m getting this error from Android when using npx react-native run-android:

java.lang.RuntimeException: Unable to instantiate application <my identifier>.MainApplication: java.lang.ClassNotFoundException: Didn't find class "<my identifier>.MainApplication"

Doing npx react-native doctor gives:

 ✓ Node.js
 ✓ yarn
 ✓ Watchman - Used for watching changes in the filesystem when in development mode

Android
 ✓ ANDROID_HOME
 ✖ Android SDK - Required for building and installing your app on Android
   - Versions found: N/A
   - Version supported: 28.0.3

iOS
 ✓ Xcode - Required for building and installing your app on iOS
 ✓ CocoaPods - Required for installing iOS dependencies
 ✓ ios-deploy - Required for installing your app on a physical device with the CLI

I followed the installation instructions to the T, and it was all working correctly yesterday. That suggests to me there’s something up with the environment variables but I can’t work out what it is. Here’s my .bash_profile:

export ANDROID_HOME=$HOME/Library/Android/sdk
export PATH=$PATH:$ANDROID_HOME/emulator
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/tools/bin
export PATH=$PATH:$ANDROID_HOME/platform-tools

Running source ~/.bash_profile && npx react-native doctor gives the same output as above.