- [ ] Error handling for semantic errors (e.g. ambiguous lookup, inaccessible lookup, wrong kind of thing found, instance vs static thing found, wrong type for the context, value vs variable)
- [ ] Public interface of compiler APIs, backcompat scenarios
- [ ] Determinism
- [ ] Atomicity
- [ ] Edit-and-continue
- [ ] Completeness of the specification as a guide for testing (e.g. is the spec complete enough to suggest what the compiler should do in each scenario?)