R-下载github源码并离线安装

devtools::install_github 虽然好用，但是有时候R不能与github通讯时就很尴尬。

在jupyter中使用R时需要安装IRkernel包：

1	devtools::install_github('IRkernel/IRkernel')

但是网络似乎出现了问题，but浏览器中还是可以访问这个repo的：

这时候可以考虑把repo克隆到本地后再离线安装。过程如下：

下载源码：

$ git clone https://github.com/IRkernel/IRkernel.git
Cloning into 'IRkernel'...
remote: Enumerating objects: 12, done.
remote: Counting objects: 100% (12/12), done.
remote: Compressing objects: 100% (11/11), done.
remote: Total 2359 (delta 3), reused 4 (delta 1), pack-reused 2347
Receiving objects: 100% (2359/2359), 694.02 KiB | 30.00 KiB/s, done.
Resolving deltas: 100% (1401/1401), done.

编译：需要用到命令行编译，如果git bash中能够检测到R可以直接在git bash中编译和安装

1 2	$ which R /d/Program/R/R-4.0.2/bin/R

$ R CMD build IRkernel
* checking for file 'IRkernel/DESCRIPTION' ... OK
* preparing 'IRkernel':
* checking DESCRIPTION meta-information ... OK
* checking for LF line-endings in source and make files and shell scripts
* checking for empty or unneeded directories
Removed empty directory 'IRkernel/example-notebooks'
Removed empty directory 'IRkernel/tests/testthat/jkt'
Removed empty directory 'IRkernel/tests/testthat/njr'
* building 'IRkernel_1.1.1.9000.tar.gz'

编译会生成一个以 .tar.gz 结尾的压缩包，安装它即可。

安装：需要用到命令行

$ R CMD INSTALL IRkernel_1.1.1.9000.tar.gz
* installing to library 'D:/Program/R/R-4.0.2/library'
* installing *source* package 'IRkernel' ...
** using staged installation
** R
** inst
** byte-compile and prepare package for lazy loading
** help
*** installing help indices
  converting help for package 'IRkernel'
    finding HTML links ... ▒▒▒▒
    Comm-class                              html
    CommManager-class                       html
    IRkernel-package                        html
    comm_manager                            html
    installspec                             html
    log                                     html
    main                                    html
** building package indices
** testing if installed package can be loaded from temporary location
*** arch - i386
*** arch - x64
** testing if installed package can be loaded from final location
*** arch - i386
*** arch - x64
** testing if installed package keeps a record of temporary installation path
* DONE (IRkernel)
Making 'packages.html' ... ▒▒▒▒