A method of reproducing runtime environment for debugging an application includes reading an optimizer file from a non-volatile storage medium. The optimizer file includes a runtime environment, application definition information, and a log. The log includes summaries of events, actions, and a time mark of occurrence for each of the actions. A runtime environment for debugging the application is then defined and the application runtime is set up using the application definition information in the optimizer file. Further, the method includes running the application, attaching an optimizer, and triggering each of the actions to occur at a time mark of occurrence associated with each of the actions. Then, each of the actions and associated events is analyzed by comparing the events produced by running the application with the events in the optimizer file. If a fault is produced by the triggering, a debugger is invoked to analyze the fault.