/usr/lib/ is in ruby-hiredis 0.6.1-1+b2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/hiredis/ext/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/ruby/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/2.3.0/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/2.3.0/hiredis/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/2.3.0/hiredis/ext/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/2.3.0/hiredis/ext/hiredis_ext.so
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/hiredis.rb
/usr/lib/ruby/vendor_ruby/hiredis/
/usr/lib/ruby/vendor_ruby/hiredis/connection.rb
/usr/lib/ruby/vendor_ruby/hiredis/ext/connection.rb
/usr/lib/ruby/vendor_ruby/hiredis/ext/reader.rb
/usr/lib/ruby/vendor_ruby/hiredis/reader.rb
/usr/lib/ruby/vendor_ruby/hiredis/ruby/
/usr/lib/ruby/vendor_ruby/hiredis/ruby/connection.rb
/usr/lib/ruby/vendor_ruby/hiredis/ruby/reader.rb
/usr/lib/ruby/vendor_ruby/hiredis/version.rb