title: GNU Make ignores environment variables on windows
body: <p>So, in powershell, I type</p>
  
  <pre><code>$ Set-Variable FOO
  </code></pre>
  
  <p>Then, in my makefile, I have</p>
  
  <pre><code>.PHONY: show-foo
  show-foo:
      @echo ${FOO}
  </code></pre>
  
  <p>It outputs a blank line.</p>
  
  <p>I've tried using system variables like $profile, none of the environment variables seem to be passed into the makefile.</p>
  
  <p>can someone tell me what I'm doing wrong here?</p>
  
  <p>On windows 10, using make 4.2.1</p>