Rakefile.rb
namespace :n do
  desc "Task 1"
  task :t1 do
    puts "t1"
  end
  desc "Task 2"
  task :t2 => [:t1] do
    puts "t2"
  end
end
task default: "n:t2" 
Show the defined task.
% rake -T         
rake n:t1  # Task 1
rake n:t2  # Task 2
Run the default task.
% rake
t1
t2