環境

Winows 10 64bit
Node.js v14.7.0
react-native @ 0.63.2

エラー内容

> 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...
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 6s

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

原因

OpenJDK14以降を使う場合は、gradleを6.3で指定しないとダメらしいです

対処方法

以下、2020/08/25現在の対処法
現在最新のgradleは6.6なのでそれにしました

android/gradle/wrapper/gradle-wrapper.properties

--- distributionUrl=https\://services.gradle.org/distributions/gradle-6.2-all.zip
+++ distributionUrl=https\://services.gradle.org/distributions/gradle-6.6-all.zip

参考

https://stackoverflow.com/questions/60844245/how-solve-could-not-initialize-class-org-codehaus-groovy-reflection-reflectionc
https://github.com/gradle/gradle/issues/10248