❯ gem install rails -v 5.2.6 Fetching: concurrent-ruby-1.2.2.gem (100%) Successfully installed concurrent-ruby-1.2.2 Fetching: thread_safe-0.3.6.gem (100%) Successfully installed thread_safe-0.3.6 Fetching: tzinfo-1.2.11.gem (100%) Successfully installed tzinfo-1.2.11 Fetching: i18n-1.13.0.gem (100%) Successfully installed i18n-1.13.0 Fetching: activesupport-5.2.6.gem (100%) Successfully installed