option('rpath', type: 'feature', value: 'auto',
       description: 'whether to include rpath information in installed binaries and libraries')
option('tran-pipe', type: 'boolean', value: false,
       description: 'enable pipe transport for testing')
option('debug-logs', type: 'feature', value: 'auto',
       description: 'enable extra debugging code (default for debug builds)')