Py2/3 portability fixes in test runner

runtests.py

@@ -407,6 +407,7 @@ class CythonRunTestCase(CythonCompileTestCase):
         child_id = os.fork()
         if not child_id:
             result_code = 0
+            try:
                 try:
                     output = os.fdopen(result_handle, 'wb')
                     tests = None
@@ -741,7 +742,12 @@ if __name__ == '__main__':
                              ''')
             sys.path.insert(0, cy3_dir)
     elif sys.version_info[0] >= 3:
-        # make sure we do not import (or run) Cython itself
+        # make sure we do not import (or run) Cython itself (unless
+        # 2to3 was already run)
+        cy3_dir = os.path.join(WORKDIR, 'Cy3')
+        if os.path.isdir(cy3_dir):
+            sys.path.insert(0, cy3_dir)
+        else:
             options.with_cython = False
         options.doctests    = False
         options.unittests   = False