SnappySmoothScroller | Android library that enables snappy smooth | RecyclerView library

Turns out it's Funktionale being a bit of a bad citizen that's causing the problem. Using class lookup (Ctrl + N on Windows) for the given class, I got two results. One of them inside the expected JetBrains annotation package, the other inside Funktionale's.

Looking at the contents of this package, you can see that it actually contains a whole bunch of externally defined annotations inside it:

I can't say why they did this instead of having these libraries declared as dependencies though.

Now, for a list of possible solutions.

1. Open up the .jar file provided by the dependency, remove the offending packages from it, repack it, and include it in your project as a local .jar file.

2. Look into hacky solutions that try to remove .class files from a Gradle dependency. I found this while looking into this, but it didn't seem to work for me.

3. Raise an issue with the library authors on GitHub and wait for a response and a new release.

4. Fork and re-publish the library with the offending packages removed.

5. Use Arrow instead. This is a new functional Kotlin library created by the maintainers of Funktionale and Kategory together. They talk about it on the a Talking Kotlin podcast episode here. Unfortunately, I don't have personal experience with either of these libraries, but it might suit your needs.