---
title: "Retry only infrastructure failures"
description: "Automatic retries are for a lost machine, not for a test shard that timed out."
url: https://starsling.dev/ci-playbooks/techniques/retry-infra-failures-only
canonicalUrl: https://starsling.dev/ci-playbooks/techniques/retry-infra-failures-only
---

# Retry only infrastructure failures

Automatic retries are for a lost machine, not for a test shard that timed out.

## How to choose an approach

This technique currently has one documented company example. Validate its prerequisites, tradeoffs and original CI environment against your repository before adapting it.

- **[Anthropic](https://starsling.dev/ci-playbooks/anthropic#retry-infra-failures-only)**: Use it when CI retries timed-out or erroring jobs automatically, and most retries end the same way the first attempt did. Check before adopting: Retries stay on for a lost runner or a process that never started.

## Apply this technique

````text
Evaluate and apply this CI technique to my repository: Retry only infrastructure failures.

Automatic retries are for a lost machine, not for a test shard that timed out.

Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/retry-infra-failures-only.md

Inspect this repository’s CI workflows, build and test commands, dependencies, and recent run timings. Identify where this technique applies and explain the expected benefit using this repository’s evidence.
Measure a baseline from recent comparable runs: elapsed time, queue time, runner minutes and failures where available. If data is unavailable, say what cannot be measured.
Compare relevant company approaches, checking prerequisites, platform differences and tradeoffs. Rank applicable options by evidence, fit and measurable opportunity; do not present company results as predictions for this repo.
Recommend the smallest safe change, show what checks and fallback paths remain, and ASK ME WHICH CHANGE TO APPROVE BEFORE EDITING ANY FILES.
Only after approval, work on a new feature branch, make one reversible change, and open a reviewable pull request. Never merge or push to a default or protected branch.
Keep required checks, test coverage, deployment and release behavior intact. Validate the change and compare equivalent runs where possible; report limitations and what should be monitored after merge.
````

## How Anthropic used this technique

Read what Anthropic changed and follow the original sources.

### Anthropic: Retry only infrastructure failures

Bun's automatic retry rules matched every timed-out test shard. The change scopes them to a lost agent, so a shard that times out reports once, with no second run.

Evidence: Source PR/commit evidence

Across about 200 recent builds, about 670 automatic retries of timed-out test shards: 465 timed out again and 182 were canceled, which the PR counts as 97% wasted. ([Source](https://github.com/oven-sh/bun/pull/34684))

Use it when: CI retries timed-out or erroring jobs automatically, and most retries end the same way the first attempt did.

Before applying it: Retries stay on for a lost runner or a process that never started.

[Read more in the Anthropic playbook](https://starsling.dev/ci-playbooks/anthropic#retry-infra-failures-only)

[Primary source](https://github.com/oven-sh/bun/pull/34684)

## CI optimization is continuous work.

Apply this technique yourself, or use StarSling Runners for faster GitHub Actions and optional agent-driven optimization PRs, which teams on eligible paid plans can turn on.

[Get self-improving CI](https://starsling.dev/products/runners)

## Company Playbooks

### [Anthropic](https://starsling.dev/ci-playbooks/anthropic)

Run only affected tests

### [DoorDash](https://starsling.dev/ci-playbooks/doordash)

Run build and test in parallel, sharded across CI agents

### [Linear](https://starsling.dev/ci-playbooks/linear)

Benchmark the same job on faster hardware

### [Mastra](https://starsling.dev/ci-playbooks/mastra)

StarSling runners for the slowest test workflow

### [OpenAI](https://starsling.dev/ci-playbooks/openai)

Rank CI fixes by the minutes they save

### [Ramp](https://starsling.dev/ci-playbooks/ramp)

Move a CPU-bound test suite to a faster CPU

### [Shopify](https://starsling.dev/ci-playbooks/shopify)

Let an agent iterate against one CI metric

### [Spotify](https://starsling.dev/ci-playbooks/spotify)

Build arm64 on native arm64 runners

### [Stripe](https://starsling.dev/ci-playbooks/stripe)

Run only the tests a change can reach

### [Uber](https://starsling.dev/ci-playbooks/uber)

Build the merge-queue speculations most likely to be needed