option('lua-pc', type: 'string', value: 'auto',
  description: 'pkg-config name of lua library to build against'
)
option('lua-bin', type: 'string', value: 'lua',
  description: 'path to lua binary to test against'
)
option('tests', type: 'boolean', value: true,
  description: 'build tests'
)
