ci(nix-cachix-setup): parameterize gc-max-store-size-linux

[thedavidmeister]

What

Expose a gc-max-store-size-linux input on the nix-cachix-setup composite action (default 8G, unchanged behavior), alongside the existing gc-max-store-size-macos input. The bundled cache-nix-action step now reads it instead of a hardcoded 8G.

Why

The composite is the single source of truth for the pinned third-party action SHAs (nixbuild/nix-quick-install-action, cachix/cachix-action, nix-community/cache-nix-action). It hardcoded the linux GC budget at 8G. A downstream consumer whose build wants a different budget — a small docs/subgraph build (1G) or a larger webapp build (10G) — could not reuse the composite without setting cache-nix: false and running cache-nix-action itself, which re-introduces an inline pin of that action in the consumer and defeats single-sourcing.

This unblocks rainlanguage/raindex#2724: raindex is converting its 14 workflows to consume these composites (inheriting the pins) instead of inline-pinning the shared actions, and several of those workflows need a non-8G budget.

Behavior

Default 8G keeps every current caller identical. Only callers that pass the new input change.

🤖 Generated with Claude Code

[coderabbitai]

Warning

Review limit reached

@thedavidmeister, we couldn't start this review because you've reached your PR review rate limit.

More reviews will be available in 19 minutes and 45 seconds. Learn how PR review limits work.

Your organization has used up its prepaid credits, and credit purchases are no longer available. Enable the review add-on in the billing tab to keep reviews running — you're only billed for reviews past your plan's rate limits ($0.25/file).

⌛ How to resolve this issue?

After more reviews become available, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

We recommend that you space out your commits to avoid hitting the rate limit.

🚦 How do rate limits work?

CodeRabbit enforces hourly rate limits for each developer per organization.

Our paid plans include higher PR review limits than trial, open-source, and free plans. In all cases, reviews become available again over time. During sustained high-volume PR review activity, CodeRabbit may temporarily slow when the next review becomes available.

Please see our Fair Usage Limits Policy for further information.

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: a8650ec6-f141-4c5b-b7f0-7247bcad2847

📥 Commits

Reviewing files that changed from the base of the PR and between 0574dad and afd637e.

📒 Files selected for processing (5)

• .github/actions/cache/action.yml
• .github/actions/checkout/action.yml
• .github/actions/gh-release/action.yml
• .github/actions/nix-cachix-setup/action.yml
• .github/actions/rust-cache/action.yml

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch 2026-06-15-parameterize-gc-max-store-size-linux

---

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.}