I expected these generators to be available:

$ rails g
Usage: rails generate GENERATOR [args] [options]

MiniTest:
  mini_test:controller
  mini_test:helper
  mini_test:install
  mini_test:mailer
  mini_test:model
  mini_test:scaffold

So I ran:

$ rails g mini_test:install

But got this error:

Could not find generator mini_test:install.

As for my environment, here is the relevant portion of my Gemfile:

group :test, :development do
  gem 'minitest-rails'
end

And the resulting portions of my Gemfile.lock:

minitest (2.12.1)
minitest-rails (0.0.7)
  minitest (~> 2.12)
  rails (~> 3.1)

I am now in the process of debugging this. I would appreciate any tips. In any case, I will report back.