library(caret)几天前我跑了，它奏效了。从那以后我更新了 Rtools，现在我遇到了一些我无法通过常用方法解决的错误
错误信息如下：
> library(caret)
Error: package or namespace load failed for ‘caret’:
.onLoad failed in loadNamespace() for 'tidyselect', details:
call: env_get(base_env(), "unlockBinding")
error: object 'rlang_env_get' not found
类似的tidyselect
> library(tidyselect)
Error: package or namespace load failed for ‘tidyselect’:
.onLoad failed in loadNamespace() for 'tidyselect', details:
call: env_get(base_env(), "unlockBinding")
error: object 'rlang_env_get' not found
我都试过install.packages了
install.packages("tidyselect", dependencies = c("Depends", "Suggests"))
当我这样做时，我可以加载tidyselect，但不是caret。然后我决定尝试caret:的 github 版本devtools::install_github('topepo/caret/pkg/caret')。这失败了几个错误消息：
Error in is_list(x) : object 'rlang_is_list' not found
Error : unable to load R code in package 'ggplot2'
ERROR: lazy loading failed for package 'ggplot2'
* removing 'C:/.../R/win-library/3.5/ggplot2'
* restoring previous 'C:/.../R/win-library/3.5/ggplot2'
和
Error : .onLoad failed in loadNamespace() for 'tidyselect', details:
call: env_get(base_env(), "unlockBinding")
error: object 'rlang_env_get' not found
ERROR: lazy loading failed for package 'caret'
会话信息（）：
R version 3.5.0 (2018-04-23)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)
关于我应该看什么的任何想法都会很棒。谢谢，乔尼