Rails 4, custom gem with generator 'Could not find generator' - ruby-on-rails

Question

I'm building a gem simply to go through the processes, and I'm trying to add a generator to it. When I run $ rails g, my generator shows up:
Mygem:
mygem:install
but rails doesn't recognize it
rails g mygem:install
Could not find generator mygem:install.
I have my gem pointed to the latest version in my gemfile
#mygem/lib/rails/generators/mygem_generator.rb
require 'rails/generators'
require 'rails/generators/base'
module Mygem
class InstallGenerator < Rails::Generators::Base
def test
puts 'hi'
end
end
end
.
-mygem
- lib
- generators
- mygem
mygem_generator.rb
- mygem
version.rb
mygem.rb
- pkg
mygem-0.0.1.gem
.gitignore
Gemfile
LICENSE.txt
README.md
Rakefile
mygem.gemspec
.
#mygem.gemspec
# coding: utf-8
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'mygem/version'
Gem::Specification.new do |spec|
spec.name = "mygem"
spec.version = Mygem::VERSION
spec.authors = ["me"]
spec.email = ["email#email.com"]
spec.summary = %q{lalaala}
spec.description = %q{lalalalal}
spec.homepage = ""
spec.license = "MIT"
spec.files = `git ls-files -z`.split("\x0")
spec.executables = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
spec.test_files = spec.files.grep(%r{^(test|spec|features)/})
spec.require_paths = ["lib"]
spec.add_development_dependency "bundler", "~> 1.5"
spec.add_development_dependency "rake"
end

Answer 1

We've just made a gem, and have a generator which allows you to call rails generate exception_handler:install, like this:
#lib/generators/my_gem/install_generator.rb
module MyGem
class InstallGenerator < Rails::Generators::Base
def test
puts "hi"
end
end
end
This should help you - it works for us

Answer 2

I faced this issue after publishing my first public gem, it's because the bundler, or let's say the Rails app don't have access to the actual repository with the generator (I believe so).
I kept including gem 'spree_custom_checkout'
no luck to see the gem's generator when typing rails g.
Then I did this:
gem 'spree_custom_checkout', github: '0bserver07/Spree-Custom-Checkout'
and bam the generator shows up!
steps:
I did `gem build spree_custom_checkout.gemspec.
add it to the github repo, and push to the repostiory.
link to the repository.