bug: opam fails to handle corrupted packages

[Banyc]

If your issue concerns a package not building, please report to
https://github.com/ocaml/opam-repository/issues or to the package maintainer
unless you are confident it is an issue in the opam tool itself.
If your issue concerns failures with the opam.ocaml.org website, please report to
https://github.com/ocaml/infrastructure/issues

❯ opam config report
# opam config report
# opam-version         2.3.0
# self-upgrade         no
# system               arch=arm64 os=macos os-distribution=homebrew os-version=14.5
# solver               builtin-mccs+glpk
# install-criteria     -removed,-count[avoid-version,changed],-count[version-lag,request],-count[version-lag,changed],-count[missing-depexts,changed],-changed
# upgrade-criteria     -removed,-count[avoid-version,changed],-count[version-lag,solution],-count[missing-depexts,changed],-new
# jobs                 11
# read-state           In /private/var/folders/rs/s_91mgrx38n9tg742t37h_t00000gn/T/opam-31163-a0be32/default/packages/octez-alcotezt/octez-alcotezt.17.1/opam:
unsupported or missing file format version; should be 2.0 or older

The file mentioned is a empty file.

This file bugs almost all the opam commands, following are examples:

❯ opam clean
Fatal error:
In /private/var/folders/rs/s_91mgrx38n9tg742t37h_t00000gn/T/opam-31104-37d38c/default/packages/octez-alcotezt/octez-alcotezt.17.1/opam:
unsupported or missing file format version; should be 2.0 or older

❯ opam update
Fatal error:
In /private/var/folders/rs/s_91mgrx38n9tg742t37h_t00000gn/T/opam-31191-16e3ad/default/packages/octez-alcotezt/octez-alcotezt.17.1/opam:
unsupported or missing file format version; should be 2.0 or older

And there is no way to uninstall the opam and reinstall it again since this binary was installed from script and not from any package manager like brew.

[Banyc]

feature request: provide an option to uninstall the opam on the machine in bash -c "sh <(curl -fsSL https://opam.ocaml.org/install.sh)" from the

[rjbou]

There was a corruption during the update of repository, it is an internal error. Do you remember what is the command or the context just before that error?

To fix this internal error, you can remove the directory /private/var/folders/rs/s_91mgrx38n9tg742t37h_t00000gn/T/opam-31163-a0be32/default and then launch an opam update default to reload the repository.

We should add an option to opam repository remove to be able to delete a repository even if it contains error, something like --force.

And there is no way to uninstall the opam and reinstall it again since this binary was installed from script and not from any package manager like brew.

If you want to uninstall opam, you just need to remove the binary and the opam root. If you didn't set specific paths, binary should be in /usr/local/bin/opam and the opam root in $HOME/.opam.

[Banyc]

@rjbou It could be a false statement bc it's been awhile: I did opam upgrade and ctrl+c it because it said I hadn't been update it for a long time and then so I could do opam update first.

The first fix doesn't work:

❯ rm -r /private/var/folders/rs/s_91mgrx38n9tg742t37h_t00000gn/T/opam-31163-a0be32/default

❯ opam update default
Fatal error:
In /private/var/folders/rs/s_91mgrx38n9tg742t37h_t00000gn/T/opam-45010-9a9301/default/packages/octez-alcotezt/octez-alcotezt.17.1/opam:
unsupported or missing file format version; should be 2.0 or older

The delete-and-install route works.

Thanks for the instructions!

[kit-ty-kate]

I've managed to reproduce very simply by emptying one of the opam file in repo/default/packages/... and removing the repo cache file.

We should add an option to opam repository remove to be able to delete a repository even if it contains error, something like --force.

I'm not sure opam repository remove is the right place to respond to corrupted files. I feel like it would be more logical for opam update to not take into account the previous state of the repository.
In both cases anyway, sadly, from the point of view of our code it seems that to fix this issue we need to delay the loading of the repo cache file from the repository state and only use it if needed which is quite a large change