--- a/mercurial/revlog.py	Tue Nov 27 09:44:09 2007 -0800
+++ b/mercurial/revlog.py	Wed Nov 28 08:36:55 2007 -0800
@@ -31,8 +31,13 @@
 
 class RevlogError(Exception):
     pass
+
 class LookupError(RevlogError):
-    pass
+    def __init__(self, name, message=None):
+        if message is None:
+            message = _('not found: %s') % name
+        RevlogError.__init__(self, message)
+        self.name = name
 
 def getoffset(q):
     return int(q >> 16)
@@ -516,7 +521,7 @@
         try:
             return self.nodemap[node]
         except KeyError:
-            raise LookupError(_('%s: no node %s') % (self.indexfile, hex(node)))
+            raise LookupError(hex(node), _('%s: no node %s') % (self.indexfile, hex(node)))
     def node(self, rev):
         return self.index[rev][7]
     def linkrev(self, node):
@@ -836,7 +841,8 @@
                 for n in self.nodemap:
                     if n.startswith(bin_id) and hex(n).startswith(id):
                         if node is not None:
-                            raise LookupError(_("Ambiguous identifier"))
+                            raise LookupError(hex(node),
+                                              _("Ambiguous identifier"))
                         node = n
                 if node is not None:
                     return node
@@ -855,7 +861,7 @@
         if n:
             return n
 
-        raise LookupError(_("No match found"))
+        raise LookupError(id, _("No match found"))
 
     def cmp(self, node, text):
         """compare text with a given file revision"""
@@ -1166,13 +1172,13 @@
 
             for p in (p1, p2):
                 if not p in self.nodemap:
-                    raise LookupError(_("unknown parent %s") % short(p))
+                    raise LookupError(hex(p), _("unknown parent %s") % short(p))
 
             if not chain:
                 # retrieve the parent revision of the delta chain
                 chain = p1
                 if not chain in self.nodemap:
-                    raise LookupError(_("unknown base %s") % short(chain[:4]))
+                    raise LookupError(hex(chain), _("unknown base %s") % short(chain[:4]))
 
             # full versions are inserted when the needed deltas become
             # comparable to the uncompressed text or when the previous