dune cache

[hannesm]

Dear Madam or Sir,

from ocaml/opam-repository#26951 I read that the dune cache is now enabled by default.

From #7819 (comment) I read "The cache at its current state is indeed problematic. I suppose that's why we do not enable it by default.".

Now I wonder, did you fix the issues that were reported with the dune cache? Or should I better put upper bounds for dune on my packages (to avoid me having to deal with cache issues)?

Is there a way (via environment variable? or a global config?) to disable dune's cache globally?

[nojb]

did you fix the issues that were reported with the dune cache?

As far as I know (but @rgrinberg will confirm) the main issue is that if your rule has misspecified dependencies, then dune build may not correctly rebuild the corresponding targets, even after dune clean. That is why the new default only activates the cache for built-in rules (ie OCaml compilation), and not for all user rules.

Is there a way (via environment variable? or a global config?) to disable dune's cache globally?

Yes: DUNE_CACHE=disabled via the environment or (cache disabled) in your global Dune config.

[ElectreAAS]

Did you fix the issues that were reported with the dune cache?

If I understood correctly your initial concerns, then we have indeed fixed one with the 'safe-caching' strategy implemented in #10710 & #10944: the only things that go in the cache by default are things we know to be cache-safe.

Your other concern was about unbounded disk space: this is not currently fixed, see discussion in #8274.