ci: fixup x86_64-darwin binaries

[cole-h]

Summary by CodeRabbit

• Chores
  • Optimized build pipeline configuration for improved build system efficiency.

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

[coderabbitai]

Walkthrough

The GitHub Actions build workflow is modified to use a targeted Nix package build with system-specific variable substitution instead of a root-level build, adding environment variable wiring to the build step.

Changes

Cohort / File(s)	Summary
GitHub Actions Workflow Configuration .github/workflows/build.yaml	Replaces root package build command with targeted package build using .#packages.$SYSTEM.default path; introduces SYSTEM environment variable bound to matrix nix-system value; updates build step env configuration

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

• Verify the .#packages.$SYSTEM.default path is correct for the Nix flake structure
• Confirm SYSTEM environment variable properly maps to available matrix values
• Check that environment variable substitution occurs before build execution

Poem

🐰 A workflow refined with a targeted touch,
System-specific paths mean so much,
Environment variables dance and align,
Building just what we need—how divine! ✨

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 title 'ci: fixup x86_64-darwin binaries' accurately describes the main change: a targeted fix for x86_64-darwin CI builds by modifying the build workflow to use a specific package path and system variable.
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 fixup-x64-darwin-binaries

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📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 6d05876 and b812710.

⛔ Files ignored due to path filters (1)

• flake.lock is excluded by !**/*.lock

📒 Files selected for processing (1)

• .github/workflows/build.yaml (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: build / build-artifacts (x86_64-darwin, X64-macOS, macos-latest-xlarge)
• GitHub Check: build / build-artifacts (aarch64-linux, ARM64-Linux, namespace-profile-default-arm64)
• GitHub Check: build / build-artifacts (aarch64-darwin, ARM64-macOS, macos-latest-xlarge)
• GitHub Check: build / build-artifacts (x86_64-linux, X64-Linux, ubuntu-22.04)
• GitHub Check: Nix and Rust checks

🔇 Additional comments (1)

.github/workflows/build.yaml (1)

44-47: The workflow changes are correct; the flake already supports system-specific packages.

The flake uses forEachSupportedSystem which generates packages for each system: x86_64-linux, aarch64-linux, x86_64-darwin, and aarch64-darwin. These are the default systems supported by flake utilities, matching exactly the systems in your build matrix. The pattern .#packages.$SYSTEM.default with environment variable substitution is correct and will properly target each system during the build.

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[bryango]

Can confirm that pinning to this PR as in nix-community/hydra-check@bd664a6 fixes the problem. Thank you so much!