title: Overwrite variable from makefile
body: <p>In my makefile I have a variable <code>FOO</code>:</p>
  
  <pre><code>FOO = /path/to/bar
  </code></pre>
  
  <p>Is it possible to overwrite this variable during the makefile call? Somthing like the following:</p>
  
  <pre><code>FOO=/path/to/foo make all
  </code></pre>