diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -30,7 +30,7 @@ REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_
 def flagstr(flag):
     if flag == "inline":
         return REVLOGNGINLINEDATA
-    raise RevlogError(_("unknown revlog flag %s" % flag))
+    raise RevlogError(_("unknown revlog flag %s") % flag)
 
 def hash(text, p1, p2):
     """generate a hash from the given text and its parent hashes
@@ -355,15 +355,15 @@ class revlog(object):
         fmt = v & 0xFFFF
         if fmt == REVLOGV0:
             if flags:
-                raise RevlogError(_("index %s invalid flags %x for format v0" %
-                                   (self.indexfile, flags)))
+                raise RevlogError(_("index %s invalid flags %x for format v0") %
+                                   (self.indexfile, flags))
         elif fmt == REVLOGNG:
             if flags & ~REVLOGNGINLINEDATA:
-                raise RevlogError(_("index %s invalid flags %x for revlogng" %
-                                   (self.indexfile, flags)))
+                raise RevlogError(_("index %s invalid flags %x for revlogng") %
+                                   (self.indexfile, flags))
         else:
-            raise RevlogError(_("index %s invalid format %d" %
-                               (self.indexfile, fmt)))
+            raise RevlogError(_("index %s invalid format %d") %
+                               (self.indexfile, fmt))
         self.version = v
         if v == REVLOGV0:
             self.indexformat = indexformatv0
@@ -931,8 +931,8 @@ class revlog(object):
             return
         trinfo = tr.find(self.indexfile)
         if trinfo == None:
-            raise RevlogError(_("%s not found in the transaction"  %
-                              self.indexfile))
+            raise RevlogError(_("%s not found in the transaction")  %
+                              self.indexfile)
 
         trindex = trinfo[2]
         dataoff = self.start(trindex)