无法启动模拟器。 原因：模拟器在启动前退出 en React Native when react-native run-android

Question

I am installing React Native according to this website https://medium.com/@leonardobrunolima/react-native-tips-setting-up-your-development-environment-for-windows-d326635604ea , it's very useful until I run the command react-native run-android , this is the error I receive:

info Running jetifier to migrate libraries to AndroidX. You can disable it using "--no-jetifier" flag.
Jetifier found 864 file(s) to forward-jetify. Using 8 workers...
info Starting JS server...
info Launching emulator...
error Failed to launch emulator. Reason: Emulator exited before boot..
> Task :app:transformNativeLibsWithMergeJniLibsForDebug FAILED

Deprecated Gradle features were used in this build, making it incompatible with Gradle 6.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/5.5/userguide/command_line_interface.html#sec:command_line_warnings
24 actionable tasks: 4 executed, 20 up-to-date

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:transformNativeLibsWithMergeJniLibsForDebug'.
> Could not read path 'C:\JesusApp\android\app\build\intermediates\transforms\mergeJniLibs\debug\0\lib\x86_64'.

* 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 7s

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

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:transformNativeLibsWithMergeJniLibsForDebug'.
> Could not read path 'C:\JesusApp\android\app\build\intermediates\transforms\mergeJniLibs\debug\0\lib\x86_64'.

* 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 7s

    at checkExecSyncError (child_process.js:629:11)
    at execFileSync (child_process.js:647:13)
    at runOnAllDevices (C:\JesusApp\node_modules\@react-native-community\cli-platform-android\build\commands\runAndroid\runOnAllDevices.js:94:39)
    at process._tickCallback (internal/process/next_tick.js:68:7)
    

My node version is 10, and I am working on Windows, please help, thank you.

Answer 1

1. Check your config and environment setup with instructions here , be very careful with pathes set up. Check the $PATH from your IDE's terminal.
2. check in the AVD that a particular Android OS is selected and installed for a virtual device you use (in my case it was not, I had yellow warning exclaim sign in an "Actions" column in an AVD's devices list).
3. Have your Gradle updated to at least 6.6 in the

android/gradle/wrapper/gradle-wrapper.properties

4. On Ubuntu after run I had to "push" switch-on button on the virtual device.

Finally, I got it up and running both on Windows 10 and Ubuntu 20.04 LTS with Android 30.

Answer 2

我通过执行以下步骤成功：打开 android studio > AVD Manager > Actions（单击底部图标）> Select Cool Boot Now。

Answer 3

First start the android emulator on Android Studio, then execute the react-native run-android. If it doesn´t work go to android studio and do "Build -> Clean Project"

Answer 4

In my case, I've to wipe data on the virtual device. Android Studio -> AVD -> Actions (↓) -> Wipe Data

Answer 5

I faced similar problem when executing my react-native code on Android Physical device. I am not sure if my solution will help.

We all know that ADB requires authorization from an Android device in order to communicate with it. It's only by allowing the USB debugging and validating the computer's RSA key fingerprint that we let the ADB daemon connect to our phone and control it. This is a security feature.

My phone was connected with USB and on changing USB Configuration on device, my phone gave me another prompt "Allow USB debugging?" Image available for reference . I got solution on reallow USB debugging

Answer 6

我遇到了同样的问题，只检查开发人员选项并在设备上通过usb启用调试

Answer 7

For me, the problem ended up being quite simple. Working in react-native, I was running the following command from the terminal 'npx react-native run-android' in VS CODE. Though the emulator would run fine when started from Android Studios, I received the above error when running from the terminal in VS Code.

Solution: Run VS Code as Administrator. (or your terminal in general)

Answer 8

为我工作-磁盘上没有足够的空间，检查磁盘上是否有足够的空间（模拟器安装在哪里）。

Answer 9

This might be the insufficient space in your machine or AVD or the mismatch in the configurations.

So, do the following steps to resolve this issue.

• Verify that the environment variables are set for SDK path and adb.
• Clean the project by Build -> Clean Project
• Clean AVD by Open android studio > AVD Manager > Actions (click the bottom icon) > Select Cool Boot Now .

Answer 10

In my case, cool boot and wipe data didn't work. I just uninstall the virtual device and reinstall it and then it works for me.

Answer 11

为我工作 - 重新加载系统或清理系统/android缓存./android/avd

Answer 12

For me running

adb kill-server

and

adb start-server

worked

I also runned killall 9 node before that but it was not enough. MacOS asks for saving last state before restart also Android emulator asks before quiting it. Maybe the problem happens because saving a bad state and trying to start from that bad state. Not sure but I suspect one of these.

Answer 13

删除文件app\build\intermediates\signing_config\debug\out\signing-config.json对我有用。