Periodic Archival and Troubleshooting

[mseri]

In 2025 we introduced a policy and set of processes to move unmaintained or obsolete package versions to the opam-repository-archive.

The main downside is that unmaintained packages's versions, that are not needed to build any of the maintained
ones, will periodically disappear from the repository. You can have a
look at the policy here.
If this is the case, you may encouter an opam error of the form:

[ERROR] Package conflict!
  * Missing dependency:
    - local-package-foo → local-package-bar → dune = 3.17.2 → dune.3.17.2: no longer available

When this happens, there are three ways to move forward:

• tell us about your dependencies (open an issue to this repository, please include the package and version, together with a hyperlink where it is used, so that we can "unarchive" it back to this repository);
• use in your setup the opam-repository-archive as another repository: opam repository add archive https://github.com/ocaml/opam-repository-archive
• use in your setup the opam-repository before the archiving took place: opam repo set-url default git+https://github.com/ocaml/opam-repository.git#2025-06-before-archiving-phase3 (where the tag depends on the archival that affected you)