Invoke import on importlib.machinery directly. Access an attribute to force import in delayed-import environments. Fixes #487.

1 files changed, 4 insertions, 3 deletions

diff --git a/pkg_resources/__init__.py b/pkg_resources/__init__.py
index 50b86cdb..3ecf4c64 100644
--- a/pkg_resources/__init__.py
+++ b/pkg_resources/__init__.py
@@ -60,10 +60,11 @@ except ImportError:
 from os import open as os_open
 from os.path import isdir, split
 
-# Avoid try/except due to potential problems with delayed import mechanisms.
-if sys.version_info >= (3, 3) and sys.implementation.name == "cpython":
+try:
     import importlib.machinery as importlib_machinery
-else:
+    # access attribute to force import under delayed import mechanisms.
+    importlib_machinery.__name__
+except ImportError:
     importlib_machinery = None
 
 try: