packaging: fix build with lowdown

[dliberalesso]

This PR resolves a build failure caused by a lowdown patch from nixpkgs (NixOS/nixpkgs#468178). The patch, intended for lowdown-2.0.4 on Cygwin, is incompatible with the lowdown-2.0.2 required by this project.

To fix the build failure, the lowdown package is now only overridden if the version provided by nixpkgs is older than 2.0.2. When the override occurs, the incompatible patch is not applied.

Summary by CodeRabbit

• Chores
  • Optimized dependency management to conditionally use system package versions when compatible, falling back to pinned versions when necessary.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

📝 Walkthrough

Walkthrough

The lowdown dependency binding in packaging/dependencies.nix is refactored from a fixed override to a conditional statement that reuses the existing package if its version is at least 2.0.2, otherwise applies the same override to pin version 2.0.2. The override now explicitly sets patches = [].

Changes

Cohort / File(s)	Summary
Dependency versioning packaging/dependencies.nix	Modified lowdown binding from unconditional overrideAttrs to a version-gated conditional: reuses pkgs.lowdown if version ≥ 2.0.2, else applies override with pinned version 2.0.2 and explicit empty patches list

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• packaging: fix build with lowdown 2.0.4 #284: Also modifies the lowdown binding in packaging/dependencies.nix, specifically handling postInstall attribute behavior during version pinning.

Suggested reviewers

• edolstra

Poem

🐰 A conditional hop, version-wise and true,
Reuse what works, upgrade what's new,
No patches needed when all is well,
Just pin and override when versions tell!
✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'packaging: fix build with lowdown' is directly related to the main change. The PR fixes a build issue with the lowdown package by making the override conditional, which aligns with the title's description of fixing build problems.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

---

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 (1)

packaging/dependencies.nix (1)

43-43: Consider adding a comment explaining why patches is cleared.

The explicit patches = [] is crucial to preventing the incompatible nixpkgs patch from being applied. Consider adding a brief inline comment explaining this, similar to the detailed comments for other overrides in this file (e.g., the boehmgc section).

📝 Suggested comment addition

-        patches = [ ];
+        # Clear patches to avoid incompatible nixpkgs patches (e.g., Cygwin-specific patches for 2.0.4)
+        patches = [ ];

📜 Review details

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 33f52c3 and 9815670.

📒 Files selected for processing (1)

• packaging/dependencies.nix

🔇 Additional comments (1)

packaging/dependencies.nix (1)

33-48: The patches = [] addition correctly clears nixpkgs patches when overriding to version 2.0.2.

The fix addresses the issue where nixpkgs patches don't apply when upgrading from older lowdown versions to 2.0.2. The conditional logic is sound: if nixpkgs provides lowdown ≥ 2.0.2, use it directly; otherwise, override to 2.0.2 with patches cleared. If a specific nixpkgs version has lowdown with incompatible patches, that's a nixpkgs issue separate from this override.