Gem::Commands::PristineCommand#execute

# File tmp/rubies/ruby-4.0.0/lib/rubygems/commands/pristine_command.rb, line 105
def execute
  install_dir = options[:install_dir]

  specification_record = install_dir ? Gem::SpecificationRecord.from_path(install_dir) : Gem::Specification.specification_record

  specs = if options[:all]
    specification_record.map

  # `--extensions` must be explicitly given to pristine only gems
  # with extensions.
  elsif options[:extensions_set] &&
        options[:extensions] && options[:args].empty?
    specification_record.select do |spec|
      spec.extensions && !spec.extensions.empty?
    end
  elsif options[:only_missing_extensions]
    specification_record.select(&:missing_extensions?)
  else
    get_all_gem_names.sort.flat_map do |gem_name|
      specification_record.find_all_by_name(gem_name, options[:version]).reverse
    end
  end

  specs = specs.select {|spec| spec.platform == RUBY_ENGINE || Gem::Platform.local === spec.platform || spec.platform == Gem::Platform::RUBY }

  if specs.to_a.empty?
    raise Gem::Exception,
          "Failed to find gems #{options[:args]} #{options[:version]}"
  end

  say "Restoring gems to pristine condition..."

  specs.group_by(&:full_name_with_location).values.each do |grouped_specs|
    spec = grouped_specs.find {|s| !s.default_gem? } || grouped_specs.first

    only_executables = options[:only_executables]
    only_plugins = options[:only_plugins]

    unless only_executables || only_plugins
      # Default gemspecs include changes provided by ruby-core installer that
      # can't currently be pristined (inclusion of compiled extension targets in
      # the file list). So stick to resetting executables if it's a default gem.
      only_executables = true if spec.default_gem?
    end

    if options.key? :skip
      if options[:skip].include? spec.name
        say "Skipped #{spec.full_name}, it was given through options"
        next
      end
    end

    unless spec.extensions.empty? || options[:extensions] || only_executables || only_plugins
      say "Skipped #{spec.full_name_with_location}, it needs to compile an extension"
      next
    end

    gem = spec.cache_file

    unless File.exist?(gem) || only_executables || only_plugins
      require_relative "../remote_fetcher"

      say "Cached gem for #{spec.full_name_with_location} not found, attempting to fetch..."

      dep = Gem::Dependency.new spec.name, spec.version
      found, _ = Gem::SpecFetcher.fetcher.spec_for_dependency dep

      if found.empty?
        say "Skipped #{spec.full_name}, it was not found from cache and remote sources"
        next
      end

      spec_candidate, source = found.first
      Gem::RemoteFetcher.fetcher.download spec_candidate, source.uri.to_s, spec.base_dir
    end

    env_shebang =
      if options.include? :env_shebang
        options[:env_shebang]
      else
        install_defaults = Gem::ConfigFile::PLATFORM_DEFAULTS["install"]
        install_defaults.to_s["--env-shebang"]
      end

    bin_dir = options[:bin_dir] if options[:bin_dir]

    installer_options = {
      wrappers: true,
      force: true,
      install_dir: install_dir || spec.base_dir,
      env_shebang: env_shebang,
      build_args: spec.build_args,
      bin_dir: bin_dir,
    }

    if only_executables
      installer = Gem::Installer.for_spec(spec, installer_options)
      installer.generate_bin
    elsif only_plugins
      installer = Gem::Installer.for_spec(spec, installer_options)
      installer.generate_plugins
    else
      installer = Gem::Installer.at(gem, installer_options)
      installer.install
    end

    say "Restored #{spec.full_name_with_location}"
  end
end