title: error: collect2: error: ld returned 1 exit status CS106B Stanford Qt Creator
body: <p>I am new to C++ and I have just started the CS106B course of Stanford with their online resources.</p>
  
  <p>I am currently using Ubuntu and when I try to build the sample-project in Qt Creator I get the following issue</p>
  
  <pre><code>error: collect2: error: ld returned 1 exit status
  </code></pre>
  
  <p>On my compile output I get the following:</p>
  
  <pre><code>/usr/bin/x86_64-linux-gnu-ld: cannot find -lGL
  Makefile:426: recipe for target 'sample-project' failed
  collect2: error: ld returned 1 exit status
  make: *** [sample-project] Error 1
  14:29:38: The process "/usr/bin/make" exited with code 2.
  Error while building/deploying project sample-project (kit: Desktop Qt 5.11.1 GCC 64bit)
  When executing step "Make"
  </code></pre>
  
  <p>Any help is super appreciated</p>