Fix #2470: typing backport package causes autodoc errors with python 2.7

Author: tk0miya

CHANGES

@@ -57,6 +57,7 @@ Bugs fixed
 * #2555: Fix crash on any-references with unicode.
 * #2517: wrong bookmark encoding in PDF if using LuaLaTeX
 * #2521: generated Makefile causes BSD make crashed if sphinx-build not found
+* #2470: ``typing`` backport package causes autodoc errors with python 2.7
 
 
 Release 1.4.1 (released Apr 12, 2016)

sphinx/ext/autodoc.py

@@ -35,7 +35,10 @@
 from sphinx.util.docstrings import prepare_docstring
 
 try:
-    import typing
+    if sys.version_info >= (3,):
+        import typing
+    else:
+        typing = None
 except ImportError:
     typing = None