r - packrat R 永远安装软件包

Question

我需要使用packrat才能为 R 创建一种虚拟环境。我运行了这几行

mywd<-getwd()
packrat::init(mywd)
packrat::set_opts(auto.snapshot=TRUE)

一切正常，如 R 输出所示

Initializing packrat project in directory:
- "C:/Users/marco.fumagalli/TEST_PACKRAT"

Adding these packages to packrat:
            _        
    packrat   0.4.9-3

Fetching sources for packrat (0.4.9-3) ... OK (CRAN current)
Snapshot written to "C:/Users/marco.fumagalli/TEST_PACKRAT/packrat/packrat.lock"
Installing packrat (0.4.9-3) ... 
    OK (downloaded binary)
Initialization complete!

Restarting R session...

然后我尝试lubridate使用install.packages. 包几乎没有依赖项（magrittr、stringi、和） stringr，安装所有东西需要 20 多分钟，这似乎很不寻常。Rcppglue

这些是我的会话的基本信息

R version 3.5.0 (2018-04-23)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)