title: Passing variables to pkg's pre install script
body: <p>Is there a way to install a pkg package, using the installer command line, but setting an environment variable that the pre-script inside the pkg can read while it's being executed?</p>
  
  <p>I need to set an environment variable that the pkg's pre install script can read. Is this possible?</p>
  
  <p>Another approach is more than welcome!</p>
  
  <p>Thanks,
  Carlos.</p>