src/Pure/Tools/build.scala

         Output.warning("Ignoring bad log file: " + path + (if (msg == "") "" else "\n" + msg))
         (Nil, 0.0)
       }
 
       try {
-        val info = Build_Log.Log_File(name, text).parse_session_info(name, false)
+        val info = Build_Log.Log_File(name, text).parse_session_info(name, command_timings = true)
         val session_timing = Markup.Elapsed.unapply(info.session_timing) getOrElse 0.0
         (info.command_timings, session_timing)
       }
       catch {
         case ERROR(msg) => ignore_error(msg)