title: makefile parallel clean+compile issue
body: <p>I have a simple makefile with 3 build rules:</p>
  
  <ol>
  <li>clean (that cleans the .o) </li>
  <li>debug (compiles my code with debgging stuff)</li>
  <li>release (compiles my code with optimization stuff)</li>
  </ol>
  
  <p>sometimes I want to switch between debug mode and release so I would issue this</p>
  
  <pre><code>make clean debug -j8
  </code></pre>
  
  <p>or</p>
  
  <pre><code>make clean release -j8
  </code></pre>
  
  <p>that has a drawback because while it's doing the clean stuff, the -j8 allows make to <em>jump</em> some command since the .o are still there Then those .o are removed by the clean rule and the compiler complains because it can't find those .o</p>
  
  <p>I could do something like </p>
  
  <pre><code>make clean; make debug -j8
  </code></pre>
  
  <p>but since I use an odd makefile in another dir, the command becomes</p>
  
  <pre><code>make -C ../src -f nMakefile clean ; make -C ../src -f nMakefile -j8 release
  </code></pre>
  
  <p>that is more annoying. I was wondering if there was an <strong>hiddedn-guru-mode-rule</strong> that allows me to do it in one line</p>
  
  <p>Hope it's clear enough...</p>