I read \"Relationships between Rubygems, Bundler, and RVM\" before asking it again.
Well, there are many questions like this, but people who answered say they work
Use gem env
to list the gem paths in each context.
Without RVM gem env
will report the system gem library paths.
With RVM gem env
will report the RVM-managed gem library paths.
Bundler manages application dependencies and installs into the gem library in your environment. If you are using RVM + Bundler, the gems will be installed in the RVM managed gem directories. If you are using it without RVM, bundler will install gems in the system gem directories.