All Sirius client components are delivered as installable packages. And for Java and C# they are easy to use just by putting references to appropriate binaries. The Ruby packages are easy to install but it's hard to predict in advance whether they reference properly to all necessary resources. That's because any code becomes accessible via adding reference to the path in the file rather than including package name.
The key difference is that local relative paths work OK only for local sources but when you create Ruby package and install it those paths will be applied relatively to completely different folder. So, if you run local unit tests you don't have guarantee that all the code would work in the same fashion as it would work from the gem location. For this purpose, I've added separate class of tests into Sirius Ruby client packages. This class of tests is called installation tests. The main aim of them is to make sure that all modules are properly accessible after the package is installed. And in general it verifies that packages are operational after installation process.