Notify user of missing sources when debugging into such code

When debugging into library/dependency code when its sources have not been downloaded, debugger just goes to next line. This might be confusing to the user. Would it possible to step into generated source file (with gray background and "Attach Sources..." button in the top-right corner) or somehow else notify user what is going on?

And would it possible to continue into library code after sources have been downloaded without restarting the debugging session? Or at least notify user that a restart is needed?