I’ve kept this tool for private use for a while, but I’m realizing it may be useful for other folks. It’s called snapcraft-pr, where “pr” means “pull request”. It’s essentially a set of shell scripts that dynamically create virtual environments for requested Snapcraft pull requests, and then runs snapcraft from them. It’s proven to be extremely useful for evaluating pull requests, and gives other users the ability to do the same. Ideally we’d just be able to automatically build snaps for each pull request, but we’re not there yet. This gives somewhat similar functionality.
Classic confinement is required because it runs Snapcraft.