package search bringing up stale packages

[v-gb]

I was running the following search earlier: https://ocaml.org/packages/search?q=msgpack. It returns two main packages: first msgpack, then msgpck. After looking at the first one for a bit, I realized: well, it doesn't even support ocaml 5, and the pull request to add such support hasn't been looked at. It's a bit annoying to waste time looking at a library only to realize that you can't even build it.

Out of curiosity, I listed all packages that don't support ocaml 5 (comm -23 <(opam list -A --short | sort) <(opam list -A --short --coinstallable-with=ocaml.5.0 | sort)), and there are 1600 of them vs 3300 that support ocaml 5. So on average, every third package returned by a search is uninstallable.

Maybe this could be improved somehow? Maybe by giving the user more ways to filter results. Or maybe by displaying the dependencies better (the page for msgpack does say ocaml < 5.0 so I could have seen this earlier, but sometimes the constraint comes from a dependency, for instance https://ocaml.org/p/msgpck-repr/latest is uninstallable on ocaml 5 due to https://ocaml.org/p/ocplib-json-typed/latest, due to https://ocaml.org/p/dune/2.9.3).