How to fix "android.enableSeparateAnnotationProcessing is experimental and unsupported" which is logged as a warning?

Question

I added a new option in my gradle.properties file:

android.enableSeparateAnnotationProcessing=true

But I got the following warning from the compiler/builder:

WARNING: The option setting android.enableSeparateAnnotationProcessing=true is experimental and unsupported.

Also I tried to make it false, but I got the following message:

Gradle may disable incremental compilation as the following annotation processors are not incremental: compiler-1.1.1.jar (android.arch.persistence.room:compiler:1.1.1), compiler-4.8.0.jar (com.github.bumptech.glide:compiler:4.8.0), butterknife-compiler-8.6.0.jar (com.jakewharton:butterknife-compiler:8.6.0). Consider setting the experimental feature flag android.enableSeparateAnnotationProcessing=true in the gradle.properties file to run annotation processing in a separate task and make compilation incremental.

Environment:

JRE 1.8.0_152-release-1136-b06 amd64
JVM OpenJDK 64-Bit Server VM by JetBrains s.r.o
Android Studio 3.2.1 Build #AI-181.5540.7.32.5056338
Gradle 4.10.3
Android Gradle plugin: 3.3.1

Android doc:

When you include this flag, the Android Gradle plugin executes the annotation processors in a separate task and allows the Java compilation task to run incrementally. https://developer.android.com/studio/releases/gradle-plugin

Answer 1

This is a new feature. The warning is just that. It already works.

The warning will disappear in a future version of Android Studio.