尝试在RSTUDIO中安装软件包dplyr时出错

Question

我正在尝试在RSTUDIO环境中安装dplyr软件包，并遇到错误。

 install.packages("dplyr")
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/src/contrib:
  cannot open URL 'http://cran.rstudio.com/src/contrib/PACKAGES'
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/src/contrib:
  cannot open URL 'http://cran.rstudio.com/src/contrib/PACKAGES'
Warning in install.packages :
  package ‘dplyr’ is not available (for R version 3.6.0)
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/bin/windows/contrib/3.6:
  cannot open URL 'http://cran.rstudio.com/bin/windows/contrib/3.6/PACKAGES'

可以手动访问相同的URL。