I’m a big fan of assertion and rigorous preconditions but there are times when a failure of some invariant in a minor subsystem should not be allowed to crash

I’m a big fan of assertion and rigorous preconditions but there are times when a failure of some invariant in a minor subsystem should not be allowed to crash the entire process, especially if the context makes it easy to return an error. In our project (the language server for Go) we have gotten tremendous value from telemetry: return an error, but report home the 1-bit fact that the assertion has failed. Often that fact is enough to figure out why; other times it is necessary to refine the assertion into two or more (in a later release) to get another bit or two of information about the nature of the failure.