Rtools is required to build R packages but is not currently installed

问题再现

安装包的时候出现了这个warning:

Rtools is required to build R packages but is not currently installed

解决

打开这个链接：https://cran.r-project.org/bin/windows/Rtools/

选择合适自己的R的版本的tools，下载，此处下载那个绿色的。

点击下一步安装即可。