I’m having trouble getting ca-derivations to work with a remote cache. Specifically, they never hit the cache. From looking at http logs it looks like they need to do an extra query like /realisations/sha256:d0cba4146da895178856db309b41c3a10a25acbbaa905469960605608887e409!out.doi presumably to get the drv->out mapping, but those never get uploaded.
From the nix source, it looks like registerDrvOutput is supposed to upload them. It’s called in many spots, but the most promising is store-api.cc copyPaths, since that is what happens when you upload via nix copy --to .... A bit of debug logging and it looks like it only does the register when the RealisedPath::raw has a Realisation, but they all seem to have OpaquePath instead. nix realisation info --json seems to indicate that both CA and non-CA out paths are opaquePath. The comment implies OpaquePath is non-derived stuff like nix add-to-store but that’s clearly not the case because derived paths have it too.
Before I dig further, is it documented (or can someone explain?) how those /realisations/.. are supposed to be uploaded, so I can figure out why it’s not happening?
Also, lately we’re seeing a lot of segfaults from nix, sometimes accompanied by double free or corruption (out), sometimes not. Also some error: coroutine has finished. I don’t know if it’s related to enabling ca-derivations or just coincidence, maybe someone else has noticed something like this?
thanks!