rails/rails — pull request #12475 by acapilleri (2013-10-09 07:30:22+00:00)
Title: add rubysl gem if RUBY_ENGINE is rbx

after the app creation when I try to launch rails command
the following exception is raised:

An exception occurred running bin/rails:

(LoadError)
The library "delegate" is a provided by the "rubysl-delegate" gem and needs to be
installed to be loaded.

If using Bundler, add this library or the standard library meta-gem to the
Gemfile as follows:

gem "rubysl-delegate", "~> 2.0"

OR

gem "rubysl", "~> 2.0"

....