init(context:process_started:process_had_error:process_had_output:process_finished:)

init(context: UnsafeMutableRawPointer!, process_started: ((UnsafeMutableRawPointer?, llbuild_pid_t) -> Void)!, process_had_error: ((UnsafeMutableRawPointer?, UnsafePointer<llb_data_t>?) -> Void)!, process_had_output: ((UnsafeMutableRawPointer?, UnsafePointer<llb_data_t>?) -> Void)!, process_finished: ((UnsafeMutableRawPointer?, UnsafePointer<llb_buildsystem_command_extended_result_t>?) -> Void)!)