/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/ is in ruby-activerecord-2.3 2.3.14-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/connection_pool.rb
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/connection_specification.rb
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/database_limits.rb
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/database_statements.rb
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/query_cache.rb
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/quoting.rb
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/schema_definitions.rb
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/schema_statements.rb