title: Error installing R devtools: `Error in loadNamespace`
body: <p>There was a broken <code>devtools</code> package in the system:</p>
  
  <pre><code>Error: package ‘devtools’ was built for x86_64-apple-darwin13.4.0
  </code></pre>
  
  <p>An attempt to uninstall brings no result:</p>
  
  <pre><code>Removing package from ‘/home/user/tools/R/x86_64-redhat-linux-gnu-library/3.1’
  (as ‘lib’ is unspecified)
  Error in find.package(pkgs, lib) : there is no package called ‘devtools’
  </code></pre>
  
  <p>Now I try to install it and getting an error:</p>
  
  <pre><code>install.packages("devtools")
  * installing to library ‘/tools/R/x86_64-redhat-linux-gnu-library/3.1’
  * installing *source* package ‘devtools’ ...
  ** package ‘devtools’ successfully unpacked and MD5 sums checked
  ** libs
  gcc -m64 -std=gnu99 -I/usr/include/R -DNDEBUG  -I/usr/local/include    -fpic  -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic  -c devtools.c -o devtools.o
  gcc -m64 -std=gnu99 -shared -L/usr/lib64/R/lib -L/usr/local/lib64 -o devtools.so devtools.o -L/usr/lib64/R/lib -lR
  installing to /tools/R/x86_64-redhat-linux-gnu-library/3.1/devtools/libs
  ** R
  ** inst
  ** preparing package for lazy loading
  Error in loadNamespace(j &lt;- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]) :
    object 'vI' not found
  ERROR: lazy loading failed for package ‘devtools’
  * removing ‘/tools/R/x86_64-redhat-linux-gnu-library/3.1/devtools’
  </code></pre>
  
  <p>Any ideas how to proceed? I am on CentOS6, <code>R version 3.2.3 (2015-12-10)</code></p>