pod [!] Unknown command: `package`

1. 如果没有安装过cocoapods-packager，安装cocoapods-packager，sudo gem install cocoapods-packager.

2. 如果已经安装cocoapods-packager，还是出现上面的错误，有可能是pod的安装方式不是采用gem来安装，导致引用路径不一致，或者ruby环境不一致。

方法：卸载cocoapods，参考https://www.jianshu.com/p/79863e9da974

安装最新的ruby，参考https://www.jianshu.com/p/320ed530d278

重新安装cocoapods，sudo gem install cocoapods

重新安装cocoapods-packager, sudo gem install cocoapods-packager