Gem::Installer#verify_spec

# File tmp/rubies/ruby-4.1.0-preview1/lib/rubygems/installer.rb, line 717
def verify_spec
  unless Gem::Specification::VALID_NAME_PATTERN.match?(spec.name)
    raise Gem::InstallError, "#{spec} has an invalid name"
  end

  unless /\A#{Gem::Version::VERSION_PATTERN}\z/.match?(spec.version.to_s)
    raise Gem::InstallError, "#{spec} has an invalid version"
  end

  unless /\A[\w.-]+\z/.match?(spec.platform.to_s)
    raise Gem::InstallError, "#{spec.platform} is an invalid platform"
  end

  if spec.executables.any? {|name| !name.is_a?(String) || name != File.basename(name) || /\A\.\.?\z|\R/.match?(name) }
    raise Gem::InstallError, "#{spec} has an invalid executable"
  end

  raise Gem::InstallError, "#{spec} has an invalid bindir" unless spec.bindir.is_a?(String)

  expanded_gem_dir = File.expand_path(gem_dir)
  expanded_bindir = File.expand_path(File.join(gem_dir, spec.bindir))
  unless expanded_bindir == expanded_gem_dir || expanded_bindir.start_with?("#{expanded_gem_dir}/")
    raise Gem::InstallError, "#{spec} has an invalid bindir"
  end
end