- Running layers in sub-processes did not use to work when run via

  ``python setup.py ftest`` since it tried to run setup.py with all the
  command line options. It now detects ``setup.py`` runs and we run the test
  runner directly.

CHANGES.rst

@@ -4,7 +4,10 @@ zope.testrunner Changelog
 4.3.3 (unreleased)
 ==================
 
-- Nothing changed yet.
+- Running layers in sub-processes did not use to work when run via
+  ``python setup.py ftest`` since it tried to run setup.py with all the
+  command line options. It now detects ``setup.py`` runs and we run the test
+  runner directly.
 
 
 4.3.2 (2013-03-03)

src/zope/testrunner/runner.py

@@ -418,6 +418,10 @@ def spawn_layer_in_subprocess(result, script_parts, options, features,
         # BBB
         if script_parts is None:
             script_parts = sys.argv[0:1]
+            # If we are running via setup.py, then we'll have to run the
+            # sub-process differently.
+            if script_parts[0] == 'setup.py':
+                script_parts = ['-c', 'from zope.testrunner import run; run()']
         args = [sys.executable]
         args.extend(script_parts)
         args.extend(['--resume-layer', layer_name, str(resume_number)])