Gem::SpecificationPolicy#validate_permissions

# File tmp/rubies/ruby-3.0.5/lib/rubygems/specification_policy.rb, line 227
def validate_permissions
  return if Gem.win_platform?

  @specification.files.each do |file|
    next unless File.file?(file)
    next if File.stat(file).mode & 0444 == 0444
    warning "#{file} is not world-readable"
  end

  @specification.executables.each do |name|
    exec = File.join @specification.bindir, name
    next unless File.file?(exec)
    next if File.stat(exec).executable?
    warning "#{exec} is not executable"
  end
end