diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -535,6 +535,20 @@ def is_win_9x():
     except AttributeError:
         return os.name == 'nt' and 'command' in os.environ.get('comspec', '')
 
+getuser_fallback = None
+
+def getuser():
+    '''return name of current user'''
+    try:
+        return getpass.getuser()
+    except ImportError:
+        # import of pwd will fail on windows - try fallback
+        if getuser_fallback:
+            return getuser_fallback()
+    # raised if win32api not available
+    raise Abort(_('user name not available - set USERNAME '
+                  'environment variable'))
+
 def username(uid=None):
     """Return the name of the user with the given uid.