Fix bug.

lib/tasks/exec_command.rake

@@ -158,6 +158,7 @@ namespace :exec_commands do
   end
   def update_infos_for_exec(info,update_last=false,update_array=false)
     return if @site_construct.nil?
+    info.encode!("UTF-8", :invalid => :replace, :undef => :replace, :replace => '')
     if update_last && !@site_construct.infos.empty?
       @site_construct.infos[-1] += info.to_s
     else