Nightly stability failure: 2026-09-10T03:03:34.0098584Z --- FAIL: TestResumableReader_ContextCancelAbortsBackoff (0.0

## Nightly Stability Failure

**Latest run:** https://github.com/benbjohnson/litestream/actions/runs/34431652361
**Branch:** `main`
**Commit:** `4ed7a308`
**First seen:** 2026-08-17T03:55:52.941Z
**Last seen:** 2026-09-10T03:37:26.353Z
**Occurrences:** 7
**Fingerprint:** `bd15880638259711`

### Failed Jobs

| Job | Failed step | Summary |
|---|---|---|
| Race Detector Sweep | Run tests with race detector (3x) | 2026-09-10T03:03:34.0098584Z --- FAIL: TestResumableReader_ContextCancelAbortsBackoff (0.0 |

### Failure Details

#### Race Detector Sweep

- Job: https://github.com/benbjohnson/litestream/actions/runs/34431652361/job/102728237224
- Failed step: `Run tests with race detector (3x)`
- Summary: 2026-09-10T03:03:34.0098584Z --- FAIL: TestResumableReader_ContextCancelAbortsBackoff (0.0

```text
2026-09-10T03:03:34.0098584Z --- FAIL: TestResumableReader_ContextCancelAbortsBackoff (0.00s)
2026-09-10T03:03:34.4041236Z ##[error]Process completed with exit code 1.
```

Start with TestResumableReader_ContextCancelAbortsBackoff and reproduce it using the race-detector command from the failed “Run tests with race detector (3x)” step. Review the test’s context-cancellation and backoff behavior at commit 4ed7a308. Done means the test passes reliably across repeated race-detector runs without weakening its assertions.

Written by the indexing model from the issue text.