So what I would like to do is debug a jruby project that contains a Jar. But no matter what I do I cannot seem to be able to do this. Despite all attempts, the jar does not seem to be loaded, or the classloader is not finding the classes because it is associated to a different classloader? Unsure.

But anyways, this is bone stock sort of stuff, here is a promintent Github project that illustrates the issue:

https://github.com/jruby/activerecord-jdbc-adapter

Namely, open the activerecord-jdbc-adapter-master/jdbc-mysql directory as a project, add the lib directory to the project path, add a simple test such as:

require 'rubygems'
require 'jdbc/mysql'
require 'java'

puts "enumerating..."
java.sql.DriverManager.getDrivers.each{ |e| puts e }

url = "jdbc:mysql://localhost/test"
connection = java.sql.DriverManager.getConnection url

You will frequently run into one of two classes of errors:

1. no such file to load -- jdbc/mysql

2. DriverManager.java:602:in `getConnection': java.sql.SQLException: No suitable driver found for jdbc:...

If someone could provide a specific example of debugging a ruby gem that has a JAR file located in the lib directory, a tested working example, I'd appreciate it. At this point I have not found any way to make either RubyMine or IntelliJ+Ruby-Plugin work.