option('system', type: 'boolean', value: false, description: 'Set install paths to system ones')
option('runstatedir', type: 'string', value: '', description: 'State directory for temporary sockets, pid files, etc')
option('docdir', type: 'string', value: '', description: 'documentation installation directory')
option('docs', type: 'feature', value: 'auto', description: 'whether to generate documentation')
