CI runs the test suite with cargo nextest (installed per-job via taiki-e/install-action), but cargo-nextest is absent from the flake devShell, so locally there is no nextest at all and nix develop -c cargo nextest run fails outright.
The consequence is that local verification silently diverges from CI: anyone gating a change locally reaches for cargo test, which is slower, produces different output, and does not exercise the same runner CI uses. It also forces workflow tooling into a nested nix develop -c nix shell nixpkgs#cargo-nextest --command ... just to match CI.
Add cargo-nextest to the devShell buildInputs alongside the existing tooling, and report its version in the shell banner next to the sccache and mold lines.
Note this is unlike sccache, which is deliberately not bundled because a client must version-match the host's server. nextest has no such constraint: it is a standalone runner, so pinning it in the flake is safe and makes local match CI.
Acceptance criteria
nix develop -c cargo nextest --version succeeds, and the dev shell banner reports the nextest version.
CI runs the test suite with
cargo nextest(installed per-job viataiki-e/install-action), butcargo-nextestis absent from the flake devShell, so locally there is no nextest at all andnix develop -c cargo nextest runfails outright.The consequence is that local verification silently diverges from CI: anyone gating a change locally reaches for
cargo test, which is slower, produces different output, and does not exercise the same runner CI uses. It also forces workflow tooling into a nestednix develop -c nix shell nixpkgs#cargo-nextest --command ...just to match CI.Add
cargo-nextestto the devShellbuildInputsalongside the existing tooling, and report its version in the shell banner next to the sccache and mold lines.Note this is unlike sccache, which is deliberately not bundled because a client must version-match the host's server. nextest has no such constraint: it is a standalone runner, so pinning it in the flake is safe and makes local match CI.
Acceptance criteria
nix develop -c cargo nextest --versionsucceeds, and the dev shell banner reports the nextest version.