Ruby cares nothing about backwards compatibility.
This code on lenny:
irb(main):012:0> tmpFile = Tempfile.new('_archive_')
=> #
irb(main):013:0> tmpFile.close(true)
=> nil
irb(main):014:0> tmpFile.path
=> nil
Used to do this on sarge:
irb(main):012:0> tmpFile = Tempfile.new('_archive_')
=> #
irb(main):013:0> tmpFile.close(true)
=> nil
irb(main):014:0> tmpFile.path
=> "/tmp/_archive_20090319-12089-1dphb46-0"
And sadly there are many other such examples.