…ser-setup is installed since it takes care of the configuration they advertise. This works because the post-messages filter is evaluated at printing time, i.e. after everything has been installed.
in 1.1, `opam list pkg.version` doesn't return failure when `version` is unavailable but others are. This has been fixed in 1.2, but `opam install --dry-run` is safer and works on both. The meaning is a bit different though: - `opam list` would report packages that are explicitely unavailable - `opam install --dry` reports all packages that can not be installed, e.g. because of unavailable dependencies So with this change, packages marked available on a given OCaml version but that can't be installed on that version due to dependencies will pass tests. There is no clear policy yet: such packages are dubbed "bad" by the Opam Weather Service (http://ows.irill.org). It sounds OK to let them pass and not force them to include constraints that they may not intrisically need, but OTOH it means we pass on something we didn't test, and the package may become broken later on if the dependency constraint is relaxed and they _were_ relying themselves on the OCaml version... OPAM 1.1 also didn't have `opam list --unavailable`, so it's also replaced with `opam show`, that reliably succeeds on unavailable packages but fails on non existing versions, in 1.1 and 1.2