diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
--- a/mercurial/dirstate.py
+++ b/mercurial/dirstate.py
@@ -376,7 +376,7 @@ class dirstate(object):
             del self._map[f]
 
     def _normalize(self, path, isknown):
-        normed = os.path.normcase(path)
+        normed = util.normcase(path)
         folded = self._foldmap.get(normed, None)
         if folded is None:
             if isknown or not os.path.lexists(os.path.join(self._root, path)):
diff --git a/mercurial/posix.py b/mercurial/posix.py
--- a/mercurial/posix.py
+++ b/mercurial/posix.py
@@ -164,6 +164,10 @@ def samedevice(fpath1, fpath2):
     st2 = os.lstat(fpath2)
     return st1.st_dev == st2.st_dev
 
+# os.path.normcase is a no-op, which doesn't help us on non-native filesystems
+def normcase(path):
+    return path.lower()
+
 if sys.platform == 'darwin':
     import fcntl # only needed on darwin, missing on jython
     def realpath(path):
diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -44,6 +44,7 @@ lookupreg = platform.lookupreg
 makedir = platform.makedir
 nlinks = platform.nlinks
 normpath = platform.normpath
+normcase = platform.normcase
 nulldev = platform.nulldev
 openhardlinks = platform.openhardlinks
 oslink = platform.oslink
diff --git a/mercurial/windows.py b/mercurial/windows.py
--- a/mercurial/windows.py
+++ b/mercurial/windows.py
@@ -131,6 +131,8 @@ def localpath(path):
 def normpath(path):
     return pconvert(os.path.normpath(path))
 
+normcase = os.path.normcase
+
 def realpath(path):
     '''
     Returns the true, canonical file system path equivalent to the given
diff --git a/tests/test-convert-bzr-directories.t b/tests/test-convert-bzr-directories.t
--- a/tests/test-convert-bzr-directories.t
+++ b/tests/test-convert-bzr-directories.t
@@ -165,15 +165,15 @@ divergent nested renames (issue3089)
   a => b
   $ mkdir a
   $ bzr add a
-  adding a
+  add(ed|ing) a (re)
   $ bzr mv b/c a/c
   b/c => a/c
   $ bzr status
   added:
     a/
   renamed:
-    a/ => b/
-    a/c/ => a/c/
+    a/? => b/? (re)
+    a/c/? => a/c/? (re)
   $ bzr commit -q -m 'Divergent renames'
   $ cd ..
   $ hg convert source source-hg