Warn users before manually executing a long-running recipe

I've created recipes that in some cases last 2-3 days. Forgetting how long they take to run, I've accidentally dropped important datasets and delayed projects from progressing for several days while the rebuild was pending. If the last execution of a recipe took more than an hour, I'd like to be prompted before building manually so I can be sure I want to make the output dataset unavailable for a long time.