test1.rb

require ::File.expand_path('../../../config/environment',  __FILE__)

# No memory leak

loop do
  Mkt::Task.all.each do |t|
   puts t
  end
end

test2.rb

require ::File.expand_path('../../../config/environment',  __FILE__)

# No memory leak

task = Mkt::Task.first

loop do
  task.send(:try_completion)
end

test3.rb

require ::File.expand_path('../../../config/environment',  __FILE__)

# Memory leak!

loop do
  Mkt::Task.all.each do |task|
    task.send(:try_completion)
  end
end