react-native run-android fails from terminal

Question

D:\ReactNative\AwesomeProject>react-native run-android info Running jetifier to migrate libraries to AndroidX. You can disable it using "--no-jetifier" flag. Jetifier found 863 file(s) to forward-jetify. Using 4 workers... info Starting JS server... 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... :ReactNative:Cannot run program "npx": CreateProcess error=2, The system cannot find the file specified :ReactNative:Automatic import of native modules failed.

FAILURE: Build failed with an exception.

• Where: Script 'D:\ReactNative\AwesomeProject\node_modules@react-native-community\cli-platform-android\native_modules.gradle' line: 169

• What went wrong: A problem occurred evaluating script.

  Cannot invoke method getErrorStream() on null object

• 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 1s

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.

• Where: Script 'D:\ReactNative\AwesomeProject\node_modules@react-native-community\cli-platform-android\native_modules.gradle' line: 169

• What went wrong: A problem occurred evaluating script.

  Cannot invoke method getErrorStream() on null object

• 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 1s

at checkExecSyncError (child_process.js:621:11)
at execFileSync (child_process.js:639:15)
at runOnAllDevices (D:\ReactNative\AwesomeProject\node_modules\@react-native-community\cli-platform-android\build\commands\runAndroid\runOnAllDevices.js:94:39)
at processTicksAndRejections (internal/process/task_queues.js:93:5)

Answer 1

对我来说，问题出在这个 cli 上：

@react-native-community/cli-platform-android

有问题的版本：

3.0.0-alpha.7

只需运行它来安装最新的稳定版本：

npm i @react-native-community/cli-platform-android@2.9.0

2020 年更新：

如果此解决方法现在不起作用，请查看此链接以使用存储库中的最新版本，并查看您的 cli 版本以比较并使用正确的版本：

https://www.npmjs.com/package/@react-native-community/cli-platform-android

Answer 2

在 linux 上有同样的问题。我所要做的就是将 npx 全局安装到我的机器上，仅此而已。

sudo npm install -g npx

这是因为 native_modules.gradle 中的第 155 和 159 行：

def command = "${npx} --quiet react-native config"

...

cmdProcess = Runtime.getRuntime().exec(command)

它尝试执行命令，但未找到命令 npx。

Answer 3

我已经从旧项目中复制并替换了这个文件，现在它已经成功了。

node_modules@react-native-community\cli-platform-android\native_modules.gradle'