刚刚安装了具有管理员权限的Rtools35并检查了所有选项：
并运行：
> Sys.which("ls.exe")
ls.exe
"C:\\Rtools\\bin\\ls.exe"
> Sys.which("gcc.exe")
gcc.exe
""
我还手动查看了 'C:\Rtools\bin\' 并且 gcc.exe 丢失了。无法构建包。
尝试使用installr.
library(installr)
> install.rtools()
Loading required namespace: devtools
No need to install Rtools - You've got the relevant version of Rtools installed
此外，为了确定，已卸载、重新启动和重新安装。
> sessionInfo()
R version 3.5.0 (2018-04-23)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)
Matrix products: default
locale:
[1] LC_COLLATE=English_United Kingdom.1252
[2] LC_CTYPE=English_United Kingdom.1252
[3] LC_MONETARY=English_United Kingdom.1252
[4] LC_NUMERIC=C
[5] LC_TIME=English_United Kingdom.1252
attached base packages:
[1] stats graphics grDevices utils datasets methods base
loaded via a namespace (and not attached):
[1] compiler_3.5.0 tools_3.5.0 yaml_2.1.19