/usr/lib/ruby/1.8/thread.rb is in libruby1.8 1.8.7.352-2ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | unless defined? Thread
fail "Thread not available for this ruby interpreter"
end
require 'thread.so'
|