Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Fix cache invalidation in an incremental static-site builder (transitive partials, config, deletions, same-second edits)

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  "result": "I fixed the caching in `minibuild.py`. A randomized test of 400 rounds passed: after every round, `out/` matched a clean build byte for byte, and only the pages whose output changed were rewritten. Rendering and the command line are unchanged, and `build()` still returns the list of rebuilt pages.\n\n**What changed**\n- **Cache key based on content, not mtime.** For each page, the cache stores a hash of everything that affects its output:\n  - the page with all partials pulled in, including partials inside partials;\n  - the values of only the `{{var KEY}}` keys the page uses;\n  - `site_title`.\n\n  This catches partial edits at any depth, relevant config changes and edits made within the same second. Config keys a page doesn't use never trigger a rebuild.\n- **Output check by hash.** The cache also stores a hash of each output file's content. A page is skipped only if both its key and its output hash still match. Otherwise it's re-rendered, but only written if the new bytes differ from what's on disk. So deleted or hand-edited outputs get repaired, and nothing depends on timestamps.\n- **Stale files are removed.** Anything in `out/` that a clean build wouldn't produce, such as HTML for deleted pages or stray files, is deleted.\n- **Cache file format.** The cache now has a version number, and old cache files are ignored. It's written to a temporary file and then renamed into place, so an interrupted build can't leave a half-written cache.\n\n**How I tested it:** each round made random changes (pages, nested partials, config values, deleted pages, deleted or edited outputs, extra files) and reset all output timestamps. The test then checked three things: the output matched a fresh clean build exactly, a file's timestamp changed only if its content had to change, and the returned list matched those pages. On the real `site/`, the first build rebuilt all four pages and a second build rebuilt none. I deleted the `out/` and `.cache.json` files my test runs created, so `site/` is as it was. The test script is in `/tmp/t/fuzz.py`.\n\n**Not changed:** a missing partial or a non-text `site_title` still crashes the build, the same as before.",
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