demandimport: add _imp to ignore list
Mozilla is seeing an issue with demand importing of _imp
failing in pkg_resources/__init__.py:fixup_namespace_packages.
It strangely only reproduces when using a modern version of
setuptools/pip in certain scenarios. Adding _imp to the demand import
ignore list seems to make the problem go away.
--- a/mercurial/demandimport.py Mon Feb 22 23:36:04 2016 +0100
+++ b/mercurial/demandimport.py Thu Feb 25 22:35:11 2016 -0800
@@ -230,6 +230,8 @@
ignore = [
'__future__',
'_hashlib',
+ # ImportError during pkg_resources/__init__.py:fixup_namespace_package
+ '_imp',
'_xmlplus',
'fcntl',
'win32com.gen_py',