Ruby Garbage Collector not garbage collecting as expected

gistfile1.rb

class Person
  def self.destructor name
    proc{ puts "I AM DYING: #{name}"}
    
  end
  
  attr_reader :name
  def initialize name
    @name = name
     ObjectSpace.define_finalizer self, Person.destructor(name)
  end
end

p = Person.new 'John'
p = nil
GC.start
# person 'John' is not garbage collected now, why?
Person.new 'Thomas'
GC.start
# I AM DYING: John # Person 'John' is garbage collected

1. There are no guarantees whatsoever that any GC run will collect particular unreachable instances.
2. You can't rely on the GC calling your finalizers when the object is reaped. This is intentionally not defined to allow VM implementors maximum freedom for optimization.
3. The only guarantee is that all finalizers are invoked eventually*, even if it is at process termination time.

[*] unless of course there is a SegFault :)