[teamleaderleo]

CI fast guards is red on main from 9197d7f (#28864) on. The failing step is Validate repository variable defaults (tests/test_ci_repo_variable_defaults.py):

ci-repo-variables.yml:48: runs-on reads vars.RUNNER_POOLS with no literal runner label to fall back to; a fork pull request gets an empty runs-on

#28864 moved the Check repository variables job onto fromJSON(vars.RUNNER_POOLS).linux with nothing after it. This adds || 'blacksmith-32vcpu-ubuntu-2404' (the linux pool's first member). The job still reads the pool first, so it still never waits on LINUX_RUNNER.

Verified: the 41 guard steps that cover workflows, runners, variables and pools pass on this head (the variable-defaults step failed before the change).

Risk: low. One runs-on expression; the job only runs on manaflow-ai/cmux.

🤖 Generated with Claude Code

Agent session: agent session

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Summary by cubic

Fixes CI fast guards on main by giving the "Check repository variables" job's runs-on a literal fallback. After #28864 moved the job onto fromJSON(vars.RUNNER_POOLS).linux, a fork pull request gets an empty runs-on, failing the "Validate repository variable defaults" guard step.

The fallback is 'blacksmith-32vcpu-ubuntu-2404', the linux pool's first member. The job still reads the pool first, so it still never waits on LINUX_RUNNER.

^{Written for commit 7e5e89e. Summary will update on new commits.}

Summary by CodeRabbit

• Chores
  • Updated CI runner selection so repositories under manaflow-ai use the blacksmith-32vcpu-ubuntu-2404 runner when no Linux runner pool is configured. Other repositories continue to use ubuntu-24.04.

[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[teamleaderleo]

Owned by an agent session · session

[teamleaderleo]

Review (codex, router-review): SHIP at 7e5e89e

SHIP at 7e5e89e

Visual verdict: no images; Leo tries the build

No findings.

Follow-ups: none

[github-actions]

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Merge receipt for 7e5e89e5e9, merged 2026-10-31 06:58:07 UTC

• Not verified at merge: ci-status (not reported), CI fast guards (in progress), Fast static checks (in progress), web-validation (in progress)
• Verified: backend migrations applied, merge freeze, plan
• Skipped by policy: apply-production, apply-staging, close lapsed freezes, web-build, web-database-tests, web-tests
• Full suite: runs on main after merge.

Labeled merged-unverified: if main breaks near this merge, look here first.