opam repair

[lefessan]

It would be nice to have a command 'opam repair' that would repair a broken installation, so that the configuration is ok (it would verify the consistency of the installed packages, and remove any of them whose dependencies are not correctly met, and create configuration files for the current version)

[AltGr]

Not sure if this is really needed anymore:

• if there is a problem with the consistency of the universe (dependencies missing...), opam upgrade should normally do the trick. (The users can't be expected to guess that, but opam upgrade --criteria="-changed" should fix but actually not upgrade anything).
• A completely different issue, if there are bugs within OPAM internal files, I can't see a worthwile way of automatically repairing. opam switch export and recreate with opam switch import in a clean environment are your best way out.
• If there is an inconsistency between the OPAM universe and what is actually installed (manual installations or ocamlfind removes, use of opam --fake), not much we can do at the moment since we don't track installed files. Clean root and import/export are your best friends, unless you know the culprit and can opam reinstall it.

So is it worth making a shortcut for a full clean switch reinstall ?
We should also be much less likely to encounter such problems now that OPAM is more stable.

[rdicosmo]

@AltGr you can add the first remark to the documentation about setting solver preferences...

[AltGr]

Good suggestion, done :)

[AltGr]

Implemented as opam upgrade --fixup