title: Change the R default C/C++ compiler in Kubuntu Linux
body: <p>If one installs an R package that requires compilation via</p>
  
  <p><code>R CMD INSTALL package.tar.gz</code></p>
  
  <p>from the bash, R uses by default the gcc compiler. It happened now that my R-package throws a warning on Cran with a 'clang' compiler setup, that doesn't appear using the gcc compiler.</p>
  
  <p>In order to reproduce the warning now on my local machine, I would like to adjust the local compiler settings to those used on the Cran-check servers.</p>
  
  <p>I found out that it should be possible to change the R default compiler by creating a Makevars.in file somewhere in the home folder, but I cannot find where it has to be located and what has to be written there in order to make R to use 'clang' with certain warning flags enabled instead of 'gcc'.</p>
  
  <p>Has anybody already switched on his/her Linux system the R default compiler from gcc to clang and could give me a hint how to do that?</p>