title: Do I really need X11 for R on Mac?
body: <p>R version 3.5.2</p>
  
  <p>macOS version 10.14.2 mojave</p>
  
  <p>Whenever installing an R, package I see the following warning:</p>
  
  <pre><code>Warning message:
  In doTryCatch(return(expr), name, parentenv, handler) :
    unable to load shared object '/Library/Frameworks/R.framework/Resources/modules//R_X11.so':
    dlopen(/Library/Frameworks/R.framework/Resources/modules//R_X11.so, 6): Library not loaded: /opt/X11/lib/libSM.6.dylib
    Referenced from: /Library/Frameworks/R.framework/Resources/modules//R_X11.so
    Reason: image not found
  </code></pre>
  
  <p>Everything seems to work fine. ggplot2 plots get drawn,...etc.</p>
  
  <p>Do I really need to install X11 from XQuartz? 
  Is anything actually broken?</p>
  
  <p>Does it "unlock" anything?</p>