Gradle Sync Failed: Setup Project Failed: Null
As mentioned and analyzed in the Google bug tracking issue https://issuetracker.google.com/issues/118342198
The issue was produced by configuring and adding a gradle constants file within a library sub project. That means:
This gradle dependency file was integrated in the top-level gradle file
appProject/someLibrary/some_constants.gradle
at
appProject/build.gradle
by
apply from: "someLibrary/some_constants.gradle"
Removing this line fixed the sync issue.
The overall solution was to move the some_constants.gradle file to the top level folder and just import it there directly.
apply from: "some_constants.gradle"
The interesting part: This sync issue just occurred if there was ONLY a library module within the project. As soon as an app module was also present this issue didn't occur anymore.