diff -r 778dc37ce683 -r f37f9499fea8 hgdemandimport/__init__.py
--- a/hgdemandimport/__init__.py	Sun May 21 13:44:26 2017 -0700
+++ b/hgdemandimport/__init__.py	Sun May 21 12:10:53 2017 -0700
@@ -13,10 +13,57 @@
 
 from __future__ import absolute_import
 
+import sys
+
 from . import demandimportpy2 as demandimport
 
+# Extensions can add to this list if necessary.
+ignore = [
+    '__future__',
+    '_hashlib',
+    # ImportError during pkg_resources/__init__.py:fixup_namespace_package
+    '_imp',
+    '_xmlplus',
+    'fcntl',
+    'nt', # pathlib2 tests the existence of built-in 'nt' module
+    'win32com.gen_py',
+    'win32com.shell', # 'appdirs' tries to import win32com.shell
+    '_winreg', # 2.7 mimetypes needs immediate ImportError
+    'pythoncom',
+    # imported by tarfile, not available under Windows
+    'pwd',
+    'grp',
+    # imported by profile, itself imported by hotshot.stats,
+    # not available under Windows
+    'resource',
+    # this trips up many extension authors
+    'gtk',
+    # setuptools' pkg_resources.py expects "from __main__ import x" to
+    # raise ImportError if x not defined
+    '__main__',
+    '_ssl', # conditional imports in the stdlib, issue1964
+    '_sre', # issue4920
+    'rfc822',
+    'mimetools',
+    'sqlalchemy.events', # has import-time side effects (issue5085)
+    # setuptools 8 expects this module to explode early when not on windows
+    'distutils.msvc9compiler',
+    '__builtin__',
+    'builtins',
+    'urwid.command_map', # for pudb
+    ]
+
+_pypy = '__pypy__' in sys.builtin_module_names
+
+if _pypy:
+    ignore.extend([
+        # _ctypes.pointer is shadowed by "from ... import pointer" (PyPy 5)
+        '_ctypes.pointer',
+    ])
+
+demandimport.init(ignore)
+
 # Re-export.
-ignore = demandimport.ignore
 isenabled = demandimport.isenabled
 enable = demandimport.enable
 disable = demandimport.disable