I don't use bcachefs anymore (or at least for now). Broke my filesystem too many times.

@eadwu thanks for the feedback. have you reported the issues upstream? they claim it never broke
have you used some crazy setup with many devices or just one partition?

It was mainly a problem on following upstream too closely since there isn't really any set tags for a "stable" release. I don't think it was really a filesystem issue, but the integration of bcachefs and bcachefs-tools were often not in sync (or at least not when I corrupted some node/journal). And it wasn't possible to downgrade because the tree version was upgraded and thus the previous version was incompatible. The last issue I was dealing with was due to some deadlock under a high cpu load which looks like was fixed some time ago but I stopped using it around that time since I kept crashing to the point where I couldn't compile a kernel.

Eval without aliases should work now.

there should probably be an assertion that the tooling version is compatible.

Whats the best way to implement this? I'm not sure.

I don't think there is a way yet. Bcachefs is a very unstable thing still and there is not a single release, much less a stable one. The only known compatible versions are whatever is the newest.

We do have a nixos test you can use to do integration tests, I think expanding that to cover most of bcachefs' features would be the best we can do for now. A topic for a different PR though IMO.

The build wasn't consistently broken but flaky: https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.bcachefs-tools.x86_64-linux For example, it succeeded for me locally just before merging even though the same failed on Hydra (same for current 20.09), so it seems unclear whether this PR addresses the flakiness.

I don't have bcachefs on that system loaded (lsmod), just bcache 🤔

This update breaks my machine, right at mounting at boot. I will try to see whether I can fix it or get more info. Stay tuned.