Gem::SpecificationPolicy#validate_values

# File tmp/rubies/ruby-3.1.3/lib/rubygems/specification_policy.rb, line 420
def validate_values
  %w[author homepage summary files].each do |attribute|
    validate_attribute_present(attribute)
  end

  if @specification.description == @specification.summary
    warning "description and summary are identical"
  end

  # TODO: raise at some given date
  warning "deprecated autorequire specified" if @specification.autorequire

  @specification.executables.each do |executable|
    validate_shebang_line_in(executable)
  end

  @specification.files.select {|f| File.symlink?(f) }.each do |file|
    warning "#{file} is a symlink, which is not supported on all platforms"
  end
end