title: How to include a makefile gracefully even if nonexistent
body: <p>In (GNU) make how can I include additional makefiles (which might pre-set some variables) at the beginning of a (master) makefile  without an interrupting error message when the additional makefiles not exist?</p>
  
  <p>I tried at the top of the makefile</p>
  
  <pre><code>include *.make
  </code></pre>
  
  <p>in order to override defaults like</p>
  
  <pre><code>main ?= main.md
  DEPS ?= template.tpl
  </code></pre>
  
  <p>However, I do get the error:</p>
  
  <pre><code>Makefile:4: *.make: No such file or directory
  </code></pre>
  
  <p>probably because at the beginning of the makefile only definitions are allowed,not commands.</p>