This is the right answer. Unfortunately, this is very rarely practiced.

More strangely (to me), this is often addressed by adding loads of fallible/partial caching (in e.g. CICD or deployment infrastructure) for package managers rather than building and publishing temporary/per-user/per-feature ephemeral packages for dev/testing to an internal registry. Since the latter's usually less complex and more reliable, it's odd that it's so rarely practiced.