ObjectBox is not entirely FOSS

Hello ObjectBox team!

In the instructions on the README of the project, we have these instructions:

buildscript {
    ext.objectboxVersion = "3.3.1"
    repositories {        
        mavenCentral()    
    }
    dependencies {
        classpath("io.objectbox:objectbox-gradle-plugin:$objectboxVersion")
    }
}

The plugin added to the classpath is in MavenCentral, this is the latest published version.

As an educated developer, I downloaded the sources jar, so that I could validate the source code that my app is using.

Inside that file, however, there's only a README file:

Not available yet

And naturally, by downloading the Jar file, only .class files are available.

For this reason, the gradle plugin is considered proprietary code. And this has lead F-Droid - the main FLOSS Android distributor - has blocked many apps, such as

• https://github.com/LeoColman/Petals/issues/98
• https://github.com/owntracks/android/issues/1298
• https://github.com/Nonononoki/Hendroid/issues/70
• https://github.com/kiwix/kiwix-android/issues/3091

And probably more to come.

This is a very serious bug.
I imagine it's somewhere where the code is published to MavenCentral that is not including the source codes.

This issue is a blocker for anyone that wants to integrate ObjectBox to an 100% FLOSS app, such as ones deployed to F-Droid

Start with the README's ObjectBox Gradle plugin instructions and inspect the published objectbox-gradle-plugin 3.3.1 artifact and its sources JAR on Maven Central. Confirm that the release process supplies the corresponding source code rather than only the “Not available yet” README, and verify the resulting artifact can be used by FLOSS distributions.