diff -r 2dcb3d52ef41 -r 95085d747db8 contrib/import-checker.py
--- a/contrib/import-checker.py	Tue May 02 21:08:38 2017 +0900
+++ b/contrib/import-checker.py	Tue May 02 22:24:57 2017 +0900
@@ -22,6 +22,13 @@
     'mercurial.hgweb.request',
     'mercurial.i18n',
     'mercurial.node',
+    # for cffi modules to re-export pure functions
+    'mercurial.pure.base85',
+    'mercurial.pure.bdiff',
+    'mercurial.pure.diffhelpers',
+    'mercurial.pure.mpatch',
+    'mercurial.pure.osutil',
+    'mercurial.pure.parsers',
 )
 
 # Whitelist of symbols that can be directly imported.