/usr/ is in ruby-timfel-krb5-auth 0.8.3-2build5.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/
/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/2.5.0/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/2.5.0/krb5_auth.so
/usr/share/
/usr/share/doc/
/usr/share/doc/ruby-timfel-krb5-auth/
/usr/share/doc/ruby-timfel-krb5-auth/README
/usr/share/doc/ruby-timfel-krb5-auth/changelog.Debian.gz
/usr/share/doc/ruby-timfel-krb5-auth/copyright
/usr/share/doc/ruby-timfel-krb5-auth/examples/
/usr/share/doc/ruby-timfel-krb5-auth/examples/example.rb
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/2.5.0/
/usr/share/rubygems-integration/2.5.0/specifications/
/usr/share/rubygems-integration/2.5.0/specifications/timfel-krb5-auth-0.8.3.gemspec