/usr/lib/ruby/vendor_ruby/omniauth-oauth2.rb is in ruby-omniauth-oauth2 1.4.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | require "omniauth-oauth2/version" # rubocop:disable FileName
require "omniauth/strategies/oauth2"
|