it crashes due to a NoMethodError

[pcp4711]

Hi,
am I too fast?

space-invaders-master/lib/space_invaders/game_objects/image_objects/ship.rb:100:in block in retarget_gun!': undefined method x' for nil:NilClass (NoMethodError)

    bullet.target = @enemies.find(bullet.target.x)
                                               ^^
from space-invaders-master/lib/space_invaders/game_objects/image_objects/ammo.rb:52:in `block in bullets_without_target'
from space-invaders-master/lib/space_invaders/game_objects/image_objects/ammo.rb:52:in `each'
from space-invaders-master/lib/space_invaders/game_objects/image_objects/ammo.rb:52:in `bullets_without_target'
from space-invaders-master/lib/space_invaders/game_objects/image_objects/ship.rb:99:in `retarget_gun!'
from space-invaders-master/lib/space_invaders/game_objects/image_objects/ship.rb:71:in `draw'
from space-invaders-master/lib/space_invaders/scenes/main_scene.rb:50:in `each'
from space-invaders-master/lib/space_invaders/scenes/main_scene.rb:50:in `draw'
from space-invaders-master/lib/space_invaders/game.rb:21:in `draw'
from /usr/local/lib/ruby/gems/3.1.0/gems/gosu-1.4.3/lib/gosu/patches.rb:64:in `tick'
from lib/space_invaders.rb:6:in `<main>'