[zibzab]

In my case it failed to build, maybe it was a different problem, maybe the compiler had at some point emitted errors instead of warnings.

I don't remember and it doesn't really matter other than we had build issues and it was unexpected.

[steveklabnik]

Deprecation should be the only change to Error in the last six years. It hasn’t moved. If you ever get a repro would love to hear about it! This kind of thing doesn’t happen at the scale we’re at anymore, if it did there would be an uproar.