--- a/tool/Command.h	Mon Oct 25 09:57:37 2010 +0200
+++ b/tool/Command.h	Mon Oct 25 10:12:26 2010 +0200
@@ -112,7 +112,7 @@
         bool matchesSubstr(const string &) const;
         bool matchesAbbrev(const string &) const;
 
-        virtual string helpString() const = 0;
+        virtual string helpString(const string &) const = 0;
 
         typedef vector<string> StringVector;
         virtual void execute(const StringVector &) = 0;