架构x86_64的未定义符号：在GRT中

Question

我是Xcode（版本8）的新手，我下载了手势识别工具包，它是一个C ++机器学习算法＆＃34; https://github.com/nickgillian/grt＆＃34;。 问题是当我构建给定的示例时，我得到以下错误：

 Undefined symbols for architecture x86_64:
"GRT::MovingAverageFilter::MovingAverageFilter(unsigned int, unsigned int)",referenced from:
  _main in AdaBoostExample.o
 "GRT::MovingAverageFilter::~MovingAverageFilter()", referenced from:
   _main in AdaBoostExample.o