A gently upgrade of the distribution

[dinosaure]

No description provided.

[samoht]

The error message is odd:

[ERROR] No solution for vchan.dev & vchan-xen.dev & vchan-unix.dev & base.v0.14.3 & base-bigarray.base & base-bytes.base & base-threads.base & base-unix.base & bheap.2.0.0 & bigarray-compat.1.1.0 & cmdliner.1.0.4 & conf-pkg-config.2 & conf-xen.1 & cppo.1.6.8 & csexp.1.5.1 & cstruct.6.0.1 & domain-name.0.4.0 & dune.2.9.3 & dune-configurator.2.9.3 & duration.0.2.0 & fmt.0.9.0 & functoria-runtime.4.0.0~beta2 & io-page.2.4.0 & io-page-unix.2.1.0 & ipaddr.5.2.0 & logs.0.7.0 & lwt.5.5.0 & lwt-dllist.1.0.1 & macaddr.5.2.0 & mirage-flow.3.0.0 & mirage-profile.0.9.1 & mirage-runtime.4.0.0~beta2 & mirage-xen.7.0.0 & mmap.1.1.0 & num.1.4 & ocaml.4.13.1 & ocaml-base-compiler.4.13.1 & ocaml-compiler-libs.v0.12.4 & ocaml-config.2 & ocaml-options-vanilla.1 & ocamlbuild.0.14.0 & ocamlfind.1.9.3 & ocplib-endian.1.2 & ounit.2.2.5 & ounit2.2.2.5 & parsexp.v0.14.2 & ppx_cstruct.6.0.1 & ppx_derivers.1.2.1 & ppx_sexp_conv.v0.14.3 & ppxlib.0.24.0 & result.1.5 & seq.base & sexplib.v0.14.0 & sexplib0.v0.14.0 & shared-memory-ring.3.1.0 & shared-memory-ring-lwt.3.1.0 & stdlib-shims.0.3.0 & topkg.1.0.5 & xen-evtchn.2.1.0 & xen-evtchn-unix.2.1.0 & xen-gnt.4.0.0 & xen-gnt-unix.4.0.0 & xenstore.2.1.1 & xenstore_transport.1.3.0: The following dependencies couldn't be met:
          - mirage-xen -> mirage-runtime >= 4.0
              unmet availability conditions, e.g. opam-version >= "2.1.0"

Why does mirage-runtime require opam-version >= "2.1.0" ?

[dinosaure]

Why does mirage-runtime require opam-version >= "2.1.0" ?

Currently, only about mirage-runtime, we don't really need opam.2.1.0 - however, the mirage tool expects opam.2.1.0. So we don't need to put this constraint according to our eco-system. However, due to the beta release, the avoid-version is only available since opam.2.1.0, see this comment: ocaml/opam-repository#20558 (comment)

I'm not sure how to fix this situation.