Aside: the core team doesn't write manifestos. Anyone can write a manifesto; sometimes the people who do happen to be on the core team, but the manifesto is part of their day-to-day, non-core-team work. We do like for manifestos to actually present the project consensus to a certain degree, and accordingly the core team does like to review them before they're "published", but it's not the core team's role to dictate design work.
Anyway, I think having a public roadmap of where swiftpm wants to go over the next few years is a really great idea for a lot of reasons — and frankly, these apply to all of our subprojects, and we should maintaining similar roadmaps for all of them:
- It makes a very clear statement that the project maintainers don't consider the project to be "finished".
- It (hopefully) gives people confidence that the project maintainers understand the weaknesses of the current product.
- It invites an open discussion of the project's priorities, which I know can be annoying but is also really important.
- It invites people to contribute towards actually achieving those goals, as opposed to making them worry whether their contributions will be ignored as unwanted.
- It creates a certain amount of public accountability that I think is healthy for any open-source project.
Of course, the community has to understand that a "roadmap" can't be a firm commitment to deliver features on any particular schedule, but we're all software developers here, and we should all understand the difficulties in making that kind of commitment.