在这里，我尝试下载早期版本的“backports”来处理这个问题。任何想法在哪里寻找或如何解决这个问题？
> library(devtools)
Warning message:
package ‘devtools’ was built under R version 3.2.5
> install_version("backports",version="1.1.0")
Trying https://cran.rstudio.com/
Trying http://www.stats.ox.ac.uk/pub/RWin
Downloading package from url: https://cran.rstudio.com//src/contrib/Archive/backports/backports_1.1.0.tar.gz
Error in curl::curl_fetch_memory(url, handle = handle) :
Timeout was reached
> install.packages("rmarkdown")
Installing package into ‘H:/R/win-library/3.2’
(as ‘lib’ is unspecified)
There is a binary version available but the source version is later:
binary source needs_compilation
rmarkdown 1.4 1.8 FALSE
installing the source package ‘rmarkdown’
trying URL 'https://cran.rstudio.com/src/contrib/rmarkdown_1.8.tar.gz'
Content type 'application/x-gzip' length 2093181 bytes (2.0 MB)
downloaded 2.0 MB
* installing *source* package 'rmarkdown' ...
** package 'rmarkdown' successfully unpacked and MD5 sums checked
** R
** inst
** preparing package for lazy loading
Error in loadNamespace(i, c(lib.loc, .libPaths()), versionCheck = vI[[i]]) :
there is no package called 'backports'
ERROR: lazy loading failed for package 'rmarkdown'
* removing 'H:/R/win-library/3.2/rmarkdown'
* restoring previous 'H:/R/win-library/3.2/rmarkdown'
Warning in install.packages :
running command '"C:/PROGRA~1/R/R-32~1.1/bin/x64/R" CMD INSTALL -l
"H:\R\win-library\3.2" C:\Users\jacarter\AppData\Local\Temp\3\RtmpULt4Do/downloaded_packages/rmarkdown_1.8.tar.gz' had status 1
Warning in install.packages :
installation of package ‘rmarkdown’ had non-zero exit status
下载的源包在 “C：\用户\ jacarter \应用程序数据\本地\温度\ 3个\ RtmpULt4Do \ downloaded_packages”