Gem::ConfigFile#check_credentials_permissions

# File tmp/rubies/ruby-4.0.0/lib/rubygems/config_file.rb, line 261
  def check_credentials_permissions
    return if Gem.win_platform? # windows doesn't write 0600 as 0600
    return unless File.exist? credentials_path

    existing_permissions = File.stat(credentials_path).mode & 0o777

    return if existing_permissions == 0o600

    alert_error <<-ERROR
Your gem push credentials file located at:

\t#{credentials_path}

has file permissions of 0#{existing_permissions.to_s 8} but 0600 is required.

To fix this error run:

\tchmod 0600 #{credentials_path}

You should reset your credentials at:

\thttps://rubygems.org/profile/edit

if you believe they were disclosed to a third party.
    ERROR

    terminate_interaction 1
  end