opam 2.1.0 has different behaviours on macOS on packages with mismatching version field

[kit-ty-kate]

$ opam repository set-url --strict default "git://github.com/GgnDpSngh/opam-repository.git#ef9a4b1448581b3de004c85ce9409eaacee2bdd0"
[default] Initialised
[ERROR] In /home/opam/.opam/repo/default/packages/elina/elina.1.1/opam:
        This file is for package 'elina.1.1' but has mismatching fields 'version:1.3.
[ERROR] Strict mode: aborting
[ERROR] Could not update repository "default": OpamStd.OpamSys.Exit(30)

This succeeds (see #4779), but now on Linux:

$ opam pin add -k version -yn elina.1.1 1.1
elina is now pinned to version 1.1

succeeds, however on macOS the package does not even exist anymore (it existed before, see https://opam.ocaml.org/packages/elina/):

$ opam show elina
[ERROR] No package matching elina found

[kit-ty-kate]

I was able to reproduce:

$ opam repo add --strict tmp "git://github.com/GgnDpSngh/opam-repository.git#ef9a4b1448581b3de004c85ce9409eaacee2bdd0"
[tmp] Initialised
[ERROR] In /Users/kit_ty_kate/.opam/repo/tmp/packages/elina/elina.1.1/opam:
        This file is for package 'elina.1.1' but has mismatching fields 'version:1.3.
[ERROR] Strict mode: aborting
[ERROR] Could not update repository "tmp": OpamStd.OpamSys.Exit(30)
[ERROR] Initial repository fetch failed


$ opam remote
[NOTE] These are the repositories in use by the current switch. Use '--all' to see all configured repositories.

<><> Repository configuration for switch tmp ><><><><><><><><><><><><><><><>  🐫
 1 default git://github.com/ocaml/opam-repository.git


$ opam repo set-url --strict default "git://github.com/GgnDpSngh/opam-repository.git#ef9a4b1448581b3de004c85ce9409eaacee2bdd0"
[default] Initialised
[ERROR] In /Users/kit_ty_kate/.opam/repo/default/packages/elina/elina.1.1/opam:
        This file is for package 'elina.1.1' but has mismatching fields 'version:1.3.
[ERROR] Strict mode: aborting
[ERROR] Could not update repository "default": OpamStd.OpamSys.Exit(30)


$ opam repo
[NOTE] These are the repositories in use by the current switch. Use '--all' to see all configured repositories.

<><> Repository configuration for switch tmp ><><><><><><><><><><><><><><><>  🐫
 1 default git://github.com/GgnDpSngh/opam-repository.git#ef9a4b1448581b3de004c85ce9409eaacee2bdd0

$ opam show elina
[ERROR] No package matching elina found

$ opam show dune
[ERROR] No package matching dune found

There seems to be a weird change of behaviour between opam repo set-url and opam repo add where the first one sets the url dispite suceeding and the second one does not add the repository.

On macOS the repository state seems to have been set to an empty one whereas on linux it seems to have ignored the failure.

Tested with opam master (ab530f8)

[rjbou]

ok, it's the strict mode that is making it fail, i see. I've tried without it.

[rjbou]

I can reproduce, on linux too

[rjbou]

I can be better handled with the new opam repo --no-action : in case of add & set-url that fail at fetch (or check with strict mode), keep repos and mark them as non initialised

[kit-ty-kate]

I don’t think this is a good solution. I’d much rather fail early and not do any modification when it fails and have the same behaviour between add and set-url.
Otherwise that means users wouldn’t be able to revert what they did

[rjbou]

Makes sense... So we keep the may fail after setting an url just when specifically user set --no-action