Hide pre-OCaml 4.08 packages from `opam switch list-available`

[MisterDA]

I think that opam switch list-available is kind of noisy, showing OCaml packages as old as 3.07! It also says that deprecated packages are not shown. With the recent cleanup of opam-repository, maybe it's reasonable to find a way to not show old ocaml packages by default?

[rjbou]

Does ocaml/opam#6098 meet your needs?

[MisterDA]

Yes, it's great, I'm just thinking we can go further. The OCaml 4.02 package hasn't been deprecated, for instance, so it's still shown.

[kit-ty-kate]

I don't think there is anything that opam itself should or even can do here (with very small exceptions opam is language agnostic). Since opam-repository has been retiring OCaml < 4.08 it seems to be a more suited task for opam-repository to archive the old compilers.

I'll move this issue to the opam-repository issue tracker

[hannesm]

I'm not sure about that. What is the goal? IMHO we keep the old compilers in the opam-repository and have a post-install message that is sufficient.

If you like to lobby for archiving the OCaml compiler packages < 4.08, I'm all in for it. :)

[MisterDA]

It's just that having these old packages in the middle of the options, system, arch, and ocaml-variants packages is a bit annoying. What's more is that the lines and descriptions don't fit cleanly in 80 columns, and are broken in a way that I personally find hard to read.