option('deprecation_flags', type: 'boolean', value: false, description: 'use *_DISABLE_DEPRECATED flags') option('session_selector', type: 'boolean', value: false, description: 'enable building a custom session selector dialog') option('systemd', type: 'boolean', value: true, description: 'Use systemd') option('systemd_session', type: 'combo', choices: ['disable', 'enable', 'default'], value: 'default', description: 'Whether to include systemd session support and use it by default') option('systemd_journal', type: 'boolean', value:'true', description: 'Send log to systemd-journal') option('consolekit', type: 'boolean', value: false, description: 'Use consolekit') option('docbook', type: 'boolean', value: true, description: 'build documentation') option('man', type: 'boolean', value: true, description: 'build documentation (requires xmlto)')