Does this not indicate that the project might not be structured in an appropriate way that allows incrementally adding features?
In general, sooner or later you need to restructure one thing or another when requirements are changing. Good code lets you reason about a refactoring, and experience tells you when it is necessary or appropriate. Coding agents aren’t very good at the latter.
the setup is solid. there are thousands of tests and CI won't let things to merge if tests are failing.
But overall, this is pretty normal for compilers to have this sort of "unexpected" tests failing due to some work in an area. It happened to me when I was coding everything manually back in the day too
> there are thousands of tests and CI won't let things to merge if tests are failing.
That's not what a clean setup means... I mean good separation of concerns, established invariants, etc.