@boris-petrov Disclaimer. It has not been tested on JDK13, but I do not think that is the issue.
It is totally possible that the wrong GEM could have been pulled. I tested various scenarious, but there is always a chance for seomthign that behaves slightly differently.
First check that you can do is to run your build with
--debug and check that the gem resolver does.
~/.gradle/rubygems-ivyxml-cache. THat is where the Ivy cache is for the Ruby gems. It might help to with diagnosis.
1.7.0, this issue is also a show-stopper for me: jruby-gradle/jruby-gradle-plugin#393 I found today that there was a similar issue about an year ago that was fixed - perhaps the same issue is happening now...
jrubyPreparetask just hangs up... CTRL+C and rerunning it fixes it most of the times. Not sure if anyone has noticed something similar.
--infoand see and what message it hangs up.