#rake namespace alias

f.rake

namespace :f do
  
  desc "alias for `rake footasticforsure:dowork`"
  task :d
    Rake::Task["footasticforsure:dowork"].invoke
  end
end

footasticforsure.rake

namespace :footasticforsure do

  desc "foo fantastic work will be done, for sure"
  task :dowork do
    # magic
  end
end