--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -274,7 +274,7 @@ def revfix(repo, val, defval):
         try:
             num = repo.changelog.rev(repo.lookup(val))
         except KeyError:
-            raise util.Abort(_('invalid revision identifier %s'), val)
+            raise util.Abort(_('invalid revision identifier %s') % val)
     return num
 
 def revpair(ui, repo, revs):
@@ -341,7 +341,7 @@ def write_bundle(cg, filename=None, comp
     try:
         if filename:
             if os.path.exists(filename):
-                raise util.Abort(_("file '%s' already exists"), filename)
+                raise util.Abort(_("file '%s' already exists") % filename)
             fh = open(filename, "wb")
         else:
             fd, filename = tempfile.mkstemp(prefix="hg-bundle-", suffix=".hg")
@@ -1269,7 +1269,7 @@ def debugdata(ui, file_, rev):
     try:
         ui.write(r.revision(r.lookup(rev)))
     except KeyError:
-        raise util.Abort(_('invalid revision identifier %s'), rev)
+        raise util.Abort(_('invalid revision identifier %s') % rev)
 
 def debugindex(ui, file_):
     """dump the contents of an index file"""
@@ -2484,7 +2484,7 @@ def serve(ui, repo, **opts):
     try:
         httpd = hgweb.server.create_server(ui, repo)
     except socket.error, inst:
-        raise util.Abort(_('cannot start server: ') + inst.args[1])
+        raise util.Abort(_('cannot start server: %s') % inst.args[1])
 
     if ui.verbose:
         addr, port = httpd.socket.getsockname()
@@ -2734,7 +2734,7 @@ def _lookup(repo, node, branch=None):
             repo.ui.warn(_("Using head %s for branch %s\n")
                          % (short(node), branch))
         else:
-            raise util.Abort(_("branch %s not found\n") % (branch))
+            raise util.Abort(_("branch %s not found") % branch)
     else:
         node = node and repo.lookup(node) or repo.changelog.tip()
     return node
@@ -3449,7 +3449,7 @@ def dispatch(args):
         u.warn(_("abort: could not lock %s: %s\n") %
                (inst.desc or inst.filename, inst.strerror))
     except revlog.RevlogError, inst:
-        u.warn(_("abort: "), inst, "!\n")
+        u.warn(_("abort: %s!\n") % inst)
     except util.SignalInterrupt:
         u.warn(_("killed!\n"))
     except KeyboardInterrupt:
@@ -3482,7 +3482,7 @@ def dispatch(args):
         else:
             u.warn(_("abort: %s\n") % inst.strerror)
     except util.Abort, inst:
-        u.warn(_('abort: '), inst.args[0] % inst.args[1:], '\n')
+        u.warn(_("abort: %s\n") % inst)
     except TypeError, inst:
         # was this an argument error?
         tb = traceback.extract_tb(sys.exc_info()[2])