Install Rails 7 Edge Alpha

Setup your app directory

mkdir rails7-edge-alpha-app
cd rails7-edge-alpha-app

Specify your Ruby version

touch .ruby-version
echo 'ruby-3.0.0' > .ruby-version

Setup Gemfile with edge rails7

touch Gemfile
printf "source 'https://rubygems.org'\nruby '3.0.0'\n\n\ngem 'rails', github: 'rails/rails'" >> Gemfile
bundle install

edge Rails7

bundle exec rails new . --dev --force

The --dev will tell rails to use the latest development version you just installed. Otherwise Bundler will try and find gem version on RubyGems.org that are not available yet.

ta-daa!!!

bundle exec rails s