has_anchor.pp

class parent1 {
  include child1
  anchor { 'parent1::start': } ->
  Class['child1'] ->
  anchor { 'parent1'::end': }
}

class parent2 {
  include child2
  anchor { 'parent2::start': } ->
  Class['child2'] ->
  anchor { 'parent2'::end': }
}

class child1 {
  resource { 'child1': }
}

class child2 { 
  resource { 'child2': }
}

Class['parent1'] -> Class['parent2']

#expected: resource[child1] -> resource[child2] and it works!

needs_anchor.pp

class parent1 {
  include child1
}

class parent2 {
  include child2
}

class child1 {
  resource { 'child1': }
}

class child2 { 
  resource { 'child2': }
}

Class['parent1'] -> Class['parent2']

#expected: resource[child1] -> resource[child2], but no!