diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -354,12 +354,12 @@ def _dispatch(ui, args):
         d = lambda: func(ui, *args, **cmdoptions)
 
     # run pre-hook, and abort if it fails
-    ret = hook.hook(ui, repo, "pre-%s" % cmd, False, args=" ".join(fullargs))
+    ret = hook.hook(lui, repo, "pre-%s" % cmd, False, args=" ".join(fullargs))
     if ret:
         return ret
     ret = _runcommand(ui, options, cmd, d)
     # run post-hook, passing command result
-    hook.hook(ui, repo, "post-%s" % cmd, False, args=" ".join(fullargs),
+    hook.hook(lui, repo, "post-%s" % cmd, False, args=" ".join(fullargs),
               result = ret)
     return ret
 
diff --git a/mercurial/hook.py b/mercurial/hook.py
--- a/mercurial/hook.py
+++ b/mercurial/hook.py
@@ -71,7 +71,11 @@ def _pythonhook(ui, repo, name, hname, f
 def _exthook(ui, repo, name, cmd, args, throw):
     ui.note(_("running hook %s: %s\n") % (name, cmd))
     env = dict([('HG_' + k.upper(), v) for k, v in args.iteritems()])
-    r = util.system(cmd, environ=env, cwd=repo.root)
+    if repo:
+        cwd = repo.root
+    else:
+        cwd = os.getcwd()
+    r = util.system(cmd, environ=env, cwd=cwd)
     if r:
         desc, r = util.explain_exit(r)
         if throw: