Android Studio 3.X以上用R8编译，速度快，但是吃内存， 编译出现类似以下错误：

android studio

What went wrong: Execution failed for task 'Module:app:mergeDexDebug'.

> java.lang.OutOfMemoryError (no error message)

或者其他类似错误，merge dex等等错误

解决办法：

修改gradle文件： .gradle/gradle.properties照片那个配置：

## For more details on how to configure your build environment visit

# http://www.gradle.org/docs/current/userguide/build_environment.html

#

# Specifies the JVM arguments used for the daemon process.

# The setting is particularly useful for tweaking memory settings.

# Default value: -Xmx1024m -XX:MaxPermSize=256m

# org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8

#

# When configured, Gradle will run in incubating parallel mode.

# This option should only be used with decoupled projects. More details, visit

# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects

# org.gradle.parallel=true

#Sun May 05 21:04:32 CST 2019

systemProp.http.proxyHost=proxy.xxx.xxxx.net

systemProp.https.proxyPort=8080

systemProp.https.proxyHost=proxy.xxx.xxxx.net

systemProp.http.proxyPort=8080

org.gradle.jvmargs=-Xmx4g -XX\:MaxMetaspaceSize\=2g -XX\:+HeapDumpOnOutOfMemoryError -Dfile.encoding\=UTF-8