Fuzz on ClusterFuzzLite

[LucaCappelletti94]

Summary

In the past, I had configured the CI fuzzer as a simple periodic run. I have since moved to ClusterFuzzLite in all of the relevant projects I maintain, like diesel and sqlparser. Both are already deployed and have already caught several real bugs.

This runs the three existing cargo-fuzz targets on ClusterFuzzLite. Every pull request gets ten minutes of fuzzing aimed at the code it changes, and a daily batch run fuzzes for an hour and keeps its corpus on a clusterfuzzlite branch of this repository, pruned an hour before each batch. That covers what fuzz.yml did on pull requests and every night, so this removes it. The OSS-Fuzz image builds tokio under AddressSanitizer on its own nightly without the compiler crash that pinned fuzz.yml to nightly-2026-07-23. I checked the build locally through the same compile entrypoint the action runs, then fuzzed each target for a minute.

Only the batch and prune jobs request contents: write, since they push the corpus to the clusterfuzzlite branch. That branch is created on the first run.

Related issues

I haven't opened one.

Type of change

• Bug fix
• New feature
• Performance improvement
• Refactor / internal cleanup
• Documentation
• CI / build

Checklist

• make before-git-push passes locally (check, build, format, audit, test, doc-check)
• Tests added/updated for the change (coverage stays ≥ 90%)
• Both backends build (--features rustls-tls if connection/streaming code changed)
• Docs / README updated if public API changed

Performance notes

n/a

[codspeed]

Merging this PR will not alter performance

✅ 50 untouched benchmarks

---

_{Comparing LucaCappelletti94:fuzz-clusterfuzzlite (5185dc6) with main (0c2b01c)}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.32%. Comparing base (0c2b01c) to head (5185dc6).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #120      +/-   ##
==========================================
- Coverage   95.33%   95.32%   -0.02%     
==========================================
  Files          33       33              
  Lines       25346    25346              
==========================================
- Hits        24164    24160       -4     
- Misses       1182     1186       +4     

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