diff --git a/contrib/check-code.py b/contrib/check-code.py
--- a/contrib/check-code.py
+++ b/contrib/check-code.py
@@ -191,6 +191,7 @@ utestfilters = [
 
 pypats = [
   [
+    (r'\([^)]*\*\w[^()]+\w+=', "can't pass varargs with keyword in Py2.5"),
     (r'^\s*def\s*\w+\s*\(.*,\s*\(',
      "tuple parameter unpacking not available in Python 3+"),
     (r'lambda\s*\(.*,.*\)',
diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -103,8 +103,8 @@ def _runcatch(req):
             if req.repo:
                 # copy configs that were passed on the cmdline (--config) to
                 # the repo ui
-                for cfg in cfgs:
-                    req.repo.ui.setconfig(*cfg, source='--config')
+                for sec, name, val in cfgs:
+                    req.repo.ui.setconfig(sec, name, val, source='--config')
 
             # if we are in HGPLAIN mode, then disable custom debugging
             debugger = ui.config("ui", "debugger")