测试结果怎么了？

我不记得有任何问题,但似乎突然,我无法安装任何包,因为testthat没有通过测试.作为一个catch-22,我也无法安装testthat,因为它不能通过它的测试.

R version 3.0.1 (2013-05-16) -- "Good Sport"
Copyright (C) 2013 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

Error in library(testthat) : there is no package called 'testthat'
[Previously saved workspace restored]

> 
> install.packages("testthat")
Installing package into '/home/user/R/x86_64-pc-linux-gnu-library/3.0'
(as 'lib' is unspecified)
--- Please select a CRAN mirror for use in this session ---
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 14: reading configurations from ~/.fonts.conf is deprecated.
trying URL 'http://cran.cs.wwu.edu/src/contrib/testthat_0.8.1.tar.gz'
Content type 'application/x-gzip' length 40777 bytes (39 Kb)
opened URL
==================================================
downloaded 39 Kb

Error in library(testthat) : there is no package called 'testthat'
Calls: source -> withVisible -> eval -> eval -> library
Execution halted

The downloaded source packages are in
    '/tmp/RtmpMoaIPO/downloaded_packages'
Warning message:
In install.packages("testthat") :
  installation of package 'testthat' had non-zero exit status

有没有办法绕过一次安装运行的测试或以其他方式解决这个问题,以便我可以修复我的R安装？