rails: "gem install rails" won't install bundler

I’m trying to follow “Getting Started” guide ( http://guides.rubyonrails.org/getting_started.html ) and stuck in the very beginning.

I’ve create clean vagrant box with Ubuntu 15.10. Installed sqlite and executed sudo gem install rails.

gem reported 27 packages installed, but it didn’t install bundler.

So when I executed rail new blog it reported at the very end:

         run  bundle install
/usr/bin/ruby2.1: No such file or directory -- /usr/share/rubygems-integration/all/gems/bundler-1.10.6/bin/bundle (LoadError)
         run  bundle exec spring binstub --all
/usr/bin/ruby2.1: No such file or directory -- /usr/share/rubygems-integration/all/gems/bundler-1.10.6/bin/bundle (LoadError)

ruby 2.1.5p273 (2014-11-13) [x86_64-linux-gnu] gem 2.2.2 Rails 4.2.5.1

rails-bundler-console.txt