title: make: Using target specific variables in prerequisites
body: <p>I'm trying to write a Makefile where prerequisites using target specific variables</p>
  
  <pre><code>version=
  
  target1: override version=1
  target1: package
  
  target2: override version=2
  target2: package
  
  package: dir=package-${version}\
  package: source
  
  source: src/${version}.c
  </code></pre>
  
  <p>When i run make the version variable is in target package and source empty.</p>
  
  <p>What I'm doing wrong?</p>