We released Determinate Nix 3.8.1, and upstream has released Nix 2.30.1.
Please upgrade to these versions (or newer) as soon as possible.

For more information and instructions on how to upgrade, see our changelog: https://determinate.systems/posts/changelog-determinate-nix-381/

We have released Determinate Nix 3.8.1 which fixes this issue and are continuing to monitor for additional problems.

The v3 tag of determinate-nix-action has been rolled back to version 3.7.0 as well.

While we test the mitigation, we have issued a rollback to version 3.7.0.

We believe we have found the issue and are currently testing a mitigation.

At this time, we believe the issue only impacts macOS users.

Users of Determinate.pkg on macOS will get 3.7.0. You can redownload and run the macOS package to roll back. In CI, you can pin back to 3.7.0 via determinate-nix-action: https://github.com/DeterminateSystems/determinate-nix-action

We're bisecting the changes in Determinate Nix 3.8.0 and Nix 2.30.0 to identify why some builds are failing that previously succeeded. We believe the issue is related to the build-dir changes.