I only care about running with Java 10+ (well, 11+ now, if you want to be specific).
Before Java 10, Dokka could make HTML files that matched the output of what you’d expect from running the javadoc program against pure-Java source files. With Java 10, that feature of Dokka is broken. It only produces its own very different HTML files.
To answer part of my own question, I think it’s probably better to put some form of documentation into javadoc.jar than to upload an empty one. Maybe I could stick an index.html in Dokka’s output that just redirects to Dokka’s files which are in a subdirectory. I know how to make that HTML file, just not how to tell Gradle to stick it in there, or when to stick it in (between building the HTML files and jarring them up).
Is that a good idea? If so, what’s the best way to implement that in Gradle? I’d like something I could copy to other projects easily.