restore handling of lexer errors

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@13044 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/compat.ml4 b/lib/compat.ml4
index aba2720456..312860a63e 100644
--- a/lib/compat.ml4
+++ b/lib/compat.ml4
@@ -80,6 +80,7 @@ module type LexerSig = sig
   module Error : sig
     type t
     exception E of t
+    val to_string : t -> string
   end
 end