Release 3.8.0 (2025-07-10)

What's Changed

Faster CI with nix flake check

nix flake check no longer downloads flake outputs if no building is necessary.

This command is intended to validate that a flake can fully evaluate and all outputs can build. If the outputs are available in a binary cache then both properties are confirmed to be true. Notably, downloading the output from the binary cache is not strictly necessary for the validation.

Previously, nix flake check would download a flake output if the full build is available in a binary cache.

Some users will find this change significantly reduces costly bandwidth and CI workflow time.

PR: DeterminateSystems/nix-src#134

Improved flake locking of transitive dependencies

Determinate Nix now re-locks all transitive dependencies when changing a flake input's source URL.

This fixes an issue where in some scenarios Nix would not re-lock those inputs and incorrectly use the old inputs' dependencies.

PR: DeterminateSystems/nix-src#137

Full Changelog: v3.7.0...v3.8.0