title: How to set up vsvars32 environment variables?
body: <p>I'm struggling with setting my scons environment variables for visual studio 2008.<br>
  Normally I do following:</p>
  
  <pre><code>%VS90COMNTOOLS%vsvars32.bat
  
  or 
  
  call %VS90COMNTOOLS%vsvars32.bat
  </code></pre>
  
  <p>And this works in my shell.</p>
  
  <p>I try to do that in python using subprocess</p>
  
  <pre><code>subprocess.call([os.environ['VS90COMNTOOLS']+r"\vsvars32.bat"])
  </code></pre>
  
  <p>output:</p>
  
  <pre><code>d:\N\workspace&gt;scons test
  scons: Reading SConscript files ...
  Setting environment for using Microsoft Visual Studio 2008 x86 tools.
  KeyError: 'INCLUDE':
  </code></pre>
  
  <p>above invokes batch process, but environment variables are not inherited from it to my 'master process.</p>
  
  <p>When i use:</p>
  
  <pre><code>subprocess.call([os.environ['VS90COMNTOOLS']+r"\vsvars32.bat"])
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>d:\N\workspace&gt;scons test
  scons: Reading SConscript files ...
  WindowsError: [Error 2] The system cannot find the file specified:
    File "D:\N\workspace\SConstruct", line 17:
      subprocess.Popen(["call ", os.environ['VS90COMNTOOLS']+r"\vsvars32.bat"])
    File "C:\Python26\lib\subprocess.py", line 595:
      errread, errwrite)
    File "C:\Python26\lib\subprocess.py", line 821:
      startupinfo)
  </code></pre>
  
  <p>How to achieve that?</p>