R: install.packages 错误

Question

我只是想简单地安装一个包，整个过程就是 FUBAR。 本周早些时候工作正常。 没有触及防火墙设置或任何东西，并尝试在两个不同网络的两台不同机器上安装“readxl”和“dplyr”（dplyr 只是为了测试问题是否是 readxl 包），但问题仍然存在。 在我的手机上尝试了我的家庭互联网（wifi 和硬线）以及移动热点。 如何通过快速轻松地下载和安装软件包使其恢复正常？

> install.packages("readxl")
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/src/contrib:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/src/contrib/PACKAGES'
Installing package into ‘C:/Users/grant/Documents/R/win-library/3.4’
(as ‘lib’ is unspecified)
Warning in install.packages :
  InternetOpenUrl failed: 'The operation timed out'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'The operation timed out'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/src/contrib:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/src/contrib/PACKAGES'
Warning in install.packages :
  InternetOpenUrl failed: 'The operation timed out'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'The operation timed out'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/3.4:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/3.4/PACKAGES'
trying URL 'http://cran.mtu.edu/bin/windows/contrib/3.4/readxl_1.0.0.zip'
Content type 'application/zip' length 1461628 bytes (1.4 MB)
downloaded 1.4 MB

package ‘readxl’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
    C:\Users\grant\AppData\Local\Temp\Rtmpwb6TUN\downloaded_packages

@Kevin，我使用chooseCRANmirror 选择了密歇根州的CRAN 镜像，但是install.packages 仍然默认为原始的坏镜像。

> chooseCRANmirror(local.only = TRUE)
Secure CRAN mirrors 

 1: 0-Cloud [https]                 2: Australia (Canberra) [https]    3: Australia (Melbourne) [https]
 4: Australia (Perth) [https]       5: Austria [https]                 6: Belgium (Ghent) [https]      
 7: Brazil (RJ) [https]             8: Brazil (SP 1) [https]           9: Bulgaria [https]             
10: Chile 1 [https]                11: China (Lanzhou) [https]        12: Colombia (Cali) [https]      
13: Czech Republic [https]         14: Denmark [https]                15: France (Lyon 1) [https]      
16: France (Lyon 2) [https]        17: France (Marseille) [https]     18: France (Montpellier) [https] 
19: France (Paris 2) [https]       20: Germany (Münster) [https]      21: Iceland [https]              
22: Indonesia (Jakarta) [https]    23: Ireland [https]                24: Italy (Padua) [https]        
25: Japan (Tokyo) [https]          26: Malaysia [https]               27: Mexico (Mexico City) [https] 
28: Norway [https]                 29: Philippines [https]            30: Russia (Moscow) [https]      
31: Spain (A Coruña) [https]       32: Spain (Madrid) [https]         33: Sweden [https]               
34: Switzerland [https]            35: UK (Bristol) [https]           36: UK (Cambridge) [https]       
37: UK (London 1) [https]          38: USA (CA 1) [https]             39: USA (KS) [https]             
40: USA (MI 1) [https]             41: USA (TN) [https]               42: USA (TX 1) [https]           
43: USA (TX 2) [https]             44: (other mirrors)                

Selection: 40
> install.packages("dplyr")
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/src/contrib:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/src/contrib/PACKAGES'
Installing package into ‘C:/Users/grant/Documents/R/win-library/3.4’
(as ‘lib’ is unspecified)
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'The operation timed out'
Warning in install.packages :
  InternetOpenUrl failed: 'The operation timed out'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/src/contrib:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/src/contrib/PACKAGES'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  InternetOpenUrl failed: 'A connection with the server could not be established'
Warning in install.packages :
  unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/3.4:
  cannot open URL 'http://www.stats.ox.ac.uk/pub/RWin/bin/windows/contrib/3.4/PACKAGES'
trying URL 'https://cran.mtu.edu/bin/windows/contrib/3.4/dplyr_0.7.1.zip'
Content type 'application/zip' length 2881930 bytes (2.7 MB)
downloaded 2.7 MB

package ‘dplyr’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
    C:\Users\grant\AppData\Local\Temp\RtmpQXhfjF\downloaded_packages

我的默认 CRAN 镜像也已更新，但即使在重新启动 RStudio 后似乎也没有效果。

***** 临时修复 ***** 必须运行此代码：a) 在切换默认 CRAN 镜像后和 b) 在每个会话开始时。

options(repos = getOption("repos")["CRAN"])

Answer 1

我遇到了同样的问题，并且一整天都在研究它。 我尝试了几种不同的 CRAN 镜像，最后这个成功了：

install.packages('readxl', dependencies=TRUE, repos=' https://ftp.ussg.iu.edu/CRAN/ ')

下载立即发生。

Answer 2

看起来这是一个错误，在 RStudio 选项中加入了一个 CRANextra 镜像，指向一个不稳定的目的地。 据报道，RStudio 已经意识到这个问题，确认这是一个错误，并将在下一个版本中修复。

必须先更改默认 CRAN 镜像，然后在每个会话开始时仍必须运行临时解决方案。

options(repos = getOption("repos")["CRAN"])

相关文章：

警告：无法访问存储库的索引 https://www.stats.ox.ac.uk/pub/RWin/src/contrib：

安装R包的问题

感谢您帮助缩小问题范围，凯文。

Answer 3

尝试增加超时限制（也许 300 而不是 100）

选项（超时 = 300）