How to turn off only the obfuscation in Android R8?

In your gradle.properties file, add this line

 android.enableR8=false

This worked for me.

Following this answer, I was able to solve this issue. Instead of editing the build.gradle file, I added -dontobfuscate to the proguard-rules.pro file. (You can configure a different proguard rules file for debug and release builds.) This skipped the obfuscation step and allowed me to make shrink'd debug builds with R8.