rubygems has missing dependency on libopenssl-ruby in ubuntu 10.04?

[Dan Kegel]

On a clean Ubuntu 10.04 server system (perhaps created with
  sudo lxc-create -n ubu1004-demo -t ubuntu -- -r lucid
  sudo lxc-start -n ubu1004-demo
), do
  sudo apt-get install rubygems
  gem install json
This fails for me with
  /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require': no such file to load -- net/https (LoadError)
Googling for that error found
  https://github.com/aphyr/yamr/issues/3
which suggested the workaround
  sudo apt-get install libopenssl-ruby
which works.