Gem::QueryUtils#spec_loaded_from

# File tmp/rubies/ruby-3.3.0/lib/rubygems/query_utils.rb, line 304
def spec_loaded_from(entry, spec, specs)
  return unless spec.loaded_from

  if specs.length == 1
    default = spec.default_gem? ? " (default)" : nil
    entry << "\n" << "    Installed at#{default}: #{spec.base_dir}"
  else
    label = "Installed at"
    specs.each do |s|
      version = s.version.to_s
      default = ", default" if s.default_gem?
      entry << "\n" << "    #{label} (#{version}#{default}): #{s.base_dir}"
      label = " " * label.length
    end
  end
end