Unfortunately had a bug I found today in which an event_notifier genserver was calling a method that checked against the database for the the state of an Event, to decide whether to send a notification and then update the event to record that notifications were sent and upon successful update send the notifications. But in the query to construct the list of users that should be notified, the User module was not imported at the top of the file and the notifications were failing to send. Of course, if the path had ever been run, it would have obviously failed and been the simplest type of error to rectify. This is why it's generally not an issue and is actually nice as it gives you direct visibility into dependencies. But, on rare exception, when you don't test the path because it's dependent on time-dependent state and are overly confident in the suitability of the untested code you're deploying to production, you get bit by the compiler that quietly warns and lack of static analysis (oh nice writing this comment just made me discover https://github.com/rrrene/credo)
