/usr/lib/ruby/ is in ruby-compass-core 1.0.3~dfsg-3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/compass/
/usr/lib/ruby/vendor_ruby/compass/core/
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/enumerate.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/lists.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/files.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/cross_browser_support.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/colors.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/font_files.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/configuration.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/display.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/selectors.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/urls.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/env.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/image_size.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/gradient_support.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/inline_image.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/constants.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions/math.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/functions.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/monkey_patches.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/monkey_patches/
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/monkey_patches/browser_support.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions/monkey_patches/traversal.rb
/usr/lib/ruby/vendor_ruby/compass/core/generated_version.rb
/usr/lib/ruby/vendor_ruby/compass/core/caniuse.rb
/usr/lib/ruby/vendor_ruby/compass/core/version.rb
/usr/lib/ruby/vendor_ruby/compass/core/sass_extensions.rb
/usr/lib/ruby/vendor_ruby/compass/core.rb
/usr/lib/ruby/vendor_ruby/compass/error.rb
/usr/lib/ruby/vendor_ruby/compass/frameworks.rb
/usr/lib/ruby/vendor_ruby/compass/configuration/
/usr/lib/ruby/vendor_ruby/compass/configuration/paths.rb
/usr/lib/ruby/vendor_ruby/compass/configuration/inheritance.rb
/usr/lib/ruby/vendor_ruby/compass/configuration/adapters.rb
/usr/lib/ruby/vendor_ruby/compass/configuration/watch.rb
/usr/lib/ruby/vendor_ruby/compass/configuration/defaults.rb
/usr/lib/ruby/vendor_ruby/compass/configuration/data.rb
/usr/lib/ruby/vendor_ruby/compass/browser_support.rb
/usr/lib/ruby/vendor_ruby/compass/configuration.rb
/usr/lib/ruby/vendor_ruby/compass/util.rb
/usr/lib/ruby/vendor_ruby/compass-core.rb