【React Native】ビルドエラーとその解決策

1. エラー

No bundle URL present.

Make sure you're running a packager server or have included a .jsbundle file in your application bundle.

RCTFatal
__28-[RCTCxxBridge handleError:]_block_invoke
_dispatch_call_block_and_release
_dispatch_client_callout
_dispatch_main_queue_callback_4CF
__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__
__CFRunLoopRun
CFRunLoopRunSpecific
GSEventRunModal
UIApplicationMain
main
start

！！解決策！！

1. キャッシュのクリア

./node_modules/react-native/scripts/packager.sh --reset-cache

＊ビルドを停止してから実行すること。

2. エラー

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':app'.
> SDK location not found. Define location with sdk.dir in the local.properties file or with an ANDROID_HOME environment variable.

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

BUILD FAILED

Total time: 8.816 secs
Could not install the app on the device, read the error above for details.
Make sure you have an Android emulator running or a device connected and have
set up your Android development environment:
https://facebook.github.io/react-native/docs/android-setup.html

！！解決策！！

1. Android Studioの下記の項目の設定画面のパスを確認
   
Appearance & Behavior > System Settings > Android


2. 環境変数を定義する。
   
export ANDROID_HOME=/Users/userName/Library/Android/sdk (userNameは任意)


3. エラー

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:installDebug'.
> com.android.builder.testing.api.DeviceException: No connected devices!

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

BUILD FAILED

Total time: 20.689 secs
Could not install the app on the device, read the error above for details.
Make sure you have an Android emulator running or a device connected and have
set up your Android development environment:
https://facebook.github.io/react-native/docs/android-setup.html

！！解決策！！

1. 仮装端末確認(初回のみ) android list avd // 実行結果 Virtual Devices: Name: Nexus_5X_API_27 Device: Nexus 5X (Google) Path: /Users/******/.android/avd/Nexus_5X_API_27.avd Target: Google Play (Google Inc.) Based on: Android API 27 Tag/ABI: google_apis_playstore/x86 Skin: nexus_5x Sdcard: 100M
2. 仮装端末起動(端末起動していない時)

*android toolsの中にあるemulatorを使用する。

android/sdk/tools/emulator

./emulator @Nexus_5X_API_27