title: In R, using Ubuntu, try to install a lib depending on GMP C lib, it won't find GMP, but I have GMP installed
body: <p>I want to install the Rmpfr library of R, so I type within R:</p>
  
  <pre><code>install.packages("Rmpfr")
  </code></pre>
  
  <p>This package requires the GMP C library to be installed, which in Ubuntu can be installed typing on the terminal</p>
  
  <pre><code>sudo apt-get install libgmp-dev
  </code></pre>
  
  <p>So, after I try to install Rmpfr library in R, I receive an error message containing</p>
  
  <pre><code>configure: error: GNU MP not found, or not 4.1.4 or up, see http://gmplib.org
  </code></pre>
  
  <p>The problem is, I already have GNU MP installed, and its version is 5.1.2. So, something is wrong with me, maybe.</p>
  
  <p>Any clues? :-)
  Thanks!</p>