Re-work flake outputs

[lucperkins]

I noticed that this was still using defaultPackage so I fixed that and did some other sprucing-up-type things, like reformatting.

Summary by CodeRabbit

• Refactor

  • Restructured build configuration for improved system-specific package handling and organization.

• Style

  • Reformatted configuration import statements for consistency.

[coderabbitai]

Walkthrough

PR refactors Nix configuration files: reformats import expressions in default.nix and shell.nix, and substantially restructures flake.nix by updating the outputs function signature to be explicit, importing lib from nixpkgs, reorganizing devShell and packages to be per-system, and renaming system-specific package derivations.

Changes

Cohort / File(s)	Change Summary
Import Expression Formatting default.nix, shell.nix	Reformats import and fetchTarball calls to consolidate onto fewer lines; functionally equivalent with no behavioral changes.
Nix Flake Restructuring flake.nix	Expands outputs function from simple alias to explicit signature with destructuring ({ self, ... }@inputs), imports lib from nixpkgs, introduces forEachSupportedSystem helper, restructures devShell to use per-system packages attribute, reorganizes per-system package derivations into packages block with default and bootspec entries.
Integration Test Configuration synthesize/integration-test-cases/21.11-specialisations.nix	Rewrites import within configuration from inline anonymous attrSet to parenthesized function expression; syntactic restructuring with no behavioral changes.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

• flake.nix may warrant closer inspection to verify the per-system package restructuring correctly maps devShell and packages attributes and that the forEachSupportedSystem helper preserves intended functionality.
• Confirm that renaming forAllSystems to forEachSupportedSystem and the updated outputs signature don't introduce any unintended breaks in downstream references or flake evaluation.

Poem

🐰 Nix files arranged in neat little rows,
Imports and structures get a fresh repose,
Per-system packages now organized right,
Flake configurations shine oh-so-bright! ✨

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title 'Re-work flake outputs' accurately summarizes the main change: restructuring the flake.nix outputs attribute, which is the primary and most substantial modification in this changeset.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch update-flake-output-structure

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (2)

flake.nix (2)

29-45: Consider updating to devShells for consistency.

While the current devShell output works, consider aligning with the modern flake schema for consistency with the packages restructuring:

-      devShell = forEachSupportedSystem (
+      devShells = forEachSupportedSystem (
         { system, pkgs }:
-        pkgs.mkShell {
-          name = "bootspec";
-
-          packages = with pkgs; [
-            cargo
-            rustc
-            clippy
-            codespell
-            nixpkgs-fmt
-            rustfmt
-            jsonschema # provides the jv tool
-            json-schema-for-humans # provides the generate-schema-doc tool
-          ];
+        {
+          default = pkgs.mkShell {
+            name = "bootspec";
+
+            packages = with pkgs; [
+              cargo
+              rustc
+              clippy
+              codespell
+              nixpkgs-fmt
+              rustfmt
+              jsonschema # provides the jv tool
+              json-schema-for-humans # provides the generate-schema-doc tool
+            ];
+          };
         }
       );

This would mirror the packages.<system>.default pattern and align with the modern flake schema.

---

47-60: Excellent packages restructuring that addresses the PR objective!

The new per-system packages structure with default and bootspec properly replaces the deprecated defaultPackage pattern. The use of self.packages.${system}.bootspec for the default is idiomatic and avoids duplication.

Minor simplification opportunity on line 55:

-            src = inputs.self;
+            src = self;

Since self is already in scope from the function signature { self, ... }@inputs, using it directly is more concise and idiomatic.

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between d762893 and 641c145.

📒 Files selected for processing (4)

• default.nix (1 hunks)
• flake.nix (2 hunks)
• shell.nix (1 hunks)
• synthesize/integration-test-cases/21.11-specialisations.nix (1 hunks)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (5)

• GitHub Check: ValidateJsonSchema
• GitHub Check: SynthesizeIntegration
• GitHub Check: NixFormatting
• GitHub Check: format
• GitHub Check: build

🔇 Additional comments (5)

shell.nix (1)

1-4: LGTM! Clean formatting improvement.

The reformatted import expression is more concise while maintaining the same functionality.

default.nix (1)

1-4: LGTM! Consistent formatting with shell.nix.

The import expression formatting is clean and matches the style used in shell.nix.

synthesize/integration-test-cases/21.11-specialisations.nix (1)

11-18: LGTM! Improved readability.

The multi-line formatting of the function expression improves readability without changing behavior.

flake.nix (2)

6-26: Excellent modernization of the flake structure!

The explicit outputs function signature, lib import, and forEachSupportedSystem helper using lib.genAttrs are all best practices for modern Nix flakes. This provides a solid foundation for per-system outputs.

---

34-34: Good update to modern mkShell attribute!

The change from buildInputs to packages is the recommended attribute for mkShell in modern Nix.