Sorry to bust in the middle of a conversation. Is this the right place to ask questions? Just wondering, because some teams prefer to do it via forums/issues. I'm having some trouble with... calling methods. I'm trying to call a method which 100% exists in a Jar, and it works in Java environment, but I can't get it to work with jruby. Even when I try to introspect the class, it doesn't show the method. I'm feeling silly now, and I'd love a couple of tips on how to debug the issue I've prepared a simple gist to reproduce the error https://gist.github.com/Morozzzko/f0b7796e69eadbb9997dc57a2b3d4e05