add --manifest to warn if showing manifest status

[IanButterworth]

Alt to #2990

Fix #2989

Closes #2990

cc. @fingolfin @DilumAluthge

[DilumAluthge]

LGTM!

[KristofferC]

This doesn't make sense to me. Why would you then not show all packages (even those in the manifest) when you do status? The point about splitting up showing direct and indirect dependencies is that the direct dependencies are those you can directly change by changing the project file (e.g its compat) and it is those whose API you code against with the indirect dependencies being more an implementation detail of your direct dependencies. If all your packages are at the latest version but you still have some indirect dependency at the non latest version, that will not directly affect you since you are consuming the latest API of what you are depending on.

[DilumAluthge]

If I understand correctly, this isn't about ] status, right? It's about ] update.

I think that there are plenty of people that will assume that if they do ] update, it will update all packages in their environment (both direct dependencies and indirect dependencies). So, if a user does ] update, and then, after the update, one or more indirect dependencies are not at the latest version, then I absolutely think that we should print a warning to the user.

[KristofferC]

then I absolutely think that we should print a warning to the user.

I don't think so because there is nothing as a user that you can do. If you are a power user / developer that wants to go and update the compat of your dependencies then you can just do st --manifest after. Showing warnings should be done very sparingly, people getting warnings when there is nothing they can really do is not user-friendly in my opinion. It is similar to how deprecation warnings are not shown by default.