title: Disable paralled build for a specific target
body: <p>I need to disable parallel run for a single target. It is a test that verifies if program doesn't create some random or incorrectly named files. Any other file that is build in the meantime fails this test.</p>
  <p>I found this advice on <a href="https://scons.org/faq.html#How_do_I_prevent_commands_from_being_executed_in_parallel.3F" rel="nofollow noreferrer">SCons FAQ</a>:</p>
  <blockquote>
  <p>Use the SideEffect() method and specify the same dummy file for each target that shouldn't be built in parallel. Even if the file doesn't exist, SCons will prevent the simultaneous execution of commands that affect the dummy file. See the linked method page for examples.</p>
  </blockquote>
  <p>However, this is useless, as it would prevent parallel build of any two targets not only the test script.</p>
  <p>Is there any way to prevent parallel build of one target while allowing it for all others?</p>