I'm the maintainer for the p4v package and Perforce has removed a set of binaries from the official distribution and created a new installation for it. In this case, p4sandbox, was removed from the p4v package. So I have a couple questions:
1] Should I delete p4sandbox when I update the p4v package, maybe telling the user about the change?
2] If so, how do I do that?
I don't use p4sandbox and probably wouldn't create a package for it, although it would probably be pretty simple (just a clone of my p4v package), but I could at least warn users of the change.
Are you talking about deleting a file that was somehow installed by your PKGBUILD file but is not controlled by pacman?
If that's the case, don't touch the file. Just display a message that says "The file /path/blargitty is no longer needed and can be deleted."
Don't do anything special if pacman manages the file. If a file was part of the old package and is not in the new one, it will be removed. You might want to add a short information notice with an install script or just add a comment in the AUR.
Ahh, I see. Yes, it used to be installed by my p4v package, but it won't be now. So pacman will notice that it isn't installing it and will remove it? Good, that's the way I'll go. Perhaps I'll add a note in the post install that mentions it is gone.