install.packages("devtools")失败

Question

我刚开始安装软件包和R，看起来我的devtools库丢失了。

我正在尝试安装swirl，我收到了以下消息：

> install.packages("swirl")
Installing package into ‘C:/Users/cory/Documents/R/win-library/3.5’
(as ‘lib’ is unspecified)
--- Please select a CRAN mirror for use in this session ---
Warning: failed to download mirrors file (cannot open destfile 'C:\Users\cory\AppData\Local\Temp\RtmpuA5tgZ\filef6c6874433a', reason 'No such file or directory'); using local file 'C:/PROGRA~1/R/R-35~1.1/doc/CRAN_mirrors.csv'
Warning: unable to access index for repository https://cran.cnr.berkeley.edu/src/contrib:
  cannot open destfile 'C:\Users\cory\AppData\Local\Temp\RtmpuA5tgZ\filef6c4b9547', reason 'No such file or directory'
Error in gzfile(file, mode) : cannot open the connection
In addition: Warning messages:
1: package ‘swirl’ is not available (for R version 3.5.1) 
2: In gzfile(file, mode) :
  cannot open compressed file 'C:\Users\cory\AppData\Local\Temp\RtmpuA5tgZ/libloc_194_4cc5b48b.rds', probable reason 'No such file or directory'

然后，我尝试了以下方法：

> library(devtools)
Error in library(devtools) : there is no package called ‘devtools’

所以我下载了zip格式的devtools并尝试加载

> getwd()
[1] "C:/Users/cory/Documents"

我在同一个文件夹中下载了devtools压缩包，并将其重命名为devtoolz zip，然后再次尝试运行该命令

> install.packages("devtools")
Installing package into ‘C:/Users/cory/Documents/R/win-library/3.5’
(as ‘lib’ is unspecified)
Warning: unable to access index for repository http://cran.rstudio.com/src/contrib:
  cannot open destfile 'C:\Users\cory\AppData\Local\Temp\RtmpuA5tgZ\filef6c77f36a9', reason 'No such file or directory'
Error in gzfile(file, mode) : cannot open the connection
In addition: Warning messages:
1: package ‘devtools’ is not available (for R version 3.5.1) 
2: In gzfile(file, mode) :
  cannot open compressed file 'C:\Users\cory\AppData\Local\Temp\RtmpuA5tgZ/libloc_194_4cc5b48b.rds', probable reason 'No such file or directory'

我应该采取哪些步骤来安装devtools？非常感谢！:)

Answer 1

我找到了一种解决这个问题的方法，以防它对其他人有帮助：

*在Rstudio中，它可以在不从本地下载也不指向URL (我也尝试过)的情况下安装一个包。因为它与CRAN-mirrors集成在一起，所以我可以简单地在框中输入devtools，然后从现有的下拉菜单中选择它。

事实证明，它比尝试通过RGui手动导入更有效。*

Answer 2

我遇到了同样的问题，我只是关闭了我的RStudio，然后打开它，它就能工作了。