1. A method of debugging a declarative event-driven model specification, comprising: stepping through, in a debugger, execution of a compiled program generated from the declarative event-driven model specification and comprising a sequence of execution steps for execution on a computer; accessing, by the debugger during the stepping through, cross-references created during the generating of the compiled program to relate each of the execution steps of the compiled program to a corresponding element of the declarative event-driven model specification from which the execution step was generated; and iteratively performing, for each of the execution steps executed during the stepping through: communicating, by the debugger with a run-time environment that is executing the compiled program, to obtain an identification of the executed execution step; using the accessed cross-references, by the debugger, to identify a particular one of the elements from the declarative event-driven model specification that corresponds to the identified execution step; and visually highlighting, on a user interface, a visual representation of the identified particular one of the elements and a visual representation of the identified execution step.