{"answer":"I've reviewed the sweep feature end to end (`sweep.rs`, `admin.rs`, `main.rs`, `metrics.rs`, `config.rs`, `routes/mod.rs`, plus `store.rs`/`cache.rs` for the interactions). Findings:\n\n🔴 `bug` services/proxy/src/config.rs:83: `Duration::from_hours` and `Duration::from_mins` (line 84) do not exist in `std::time::Duration` — std only has `from_secs`/`from_millis`/`from_micros`/`from_nanos` — so the proxy does not compile; the whole sweep feature is dead on arrival. Needs `Duration::from_secs(3600)` / `Duration::from_secs(900)`.\n\n🟠 `bug` services/proxy/src/sweep.rs:232: `clear_partials` unlinks every file in `incoming`, including the temp files of downloads currently in flight (`BlobWriter` creates them there, store.rs:173). The write continues into the unlinked inode, then `commit`'s rename (store.rs:259) fails with ENOENT, so every concurrent fetch that spans a sweep fails with a 500 after downloading fully — routine with the default 15-minute sweep. It must skip files younger than `min_age` (or only remove files not owned by a live writer).\n\n🟠 `bug` services/proxy/src/sweep.rs:140: `forget` runs unconditionally, so a `dry_run=true` sweep deletes the index entries of blobs it would have removed — the dry run is not side-effect free as its doc and the admin route promise (admin.rs:77-79). Next request for those coordinates misses and refetches; gate it on `!dry_run`.\n\n🟠 `bug` services/proxy/src/routes/admin.rs:76: the on-demand route calls `app.sweeper.sweep(dry_run)` directly instead of `run()`, bypassing the `running` mutex, so it can execute concurrently with the background sweep — exactly the two-sweeps-over-one-directory over-eviction the module doc (sweep.rs:10-12) claims the type makes impossible.\n\n🟠 `bug` services/proxy/src/metrics.rs:94: `values()` returns `sweep_bytes_reclaimed` before `sweep_blobs_removed`, while `COUNTERS` (lines 51-57) lists blobs before bytes, so `render()` publishes the blob count under `cairn_proxy_sweep_bytes_reclaimed_total` and vice versa — the very mispairing the comment at line 30-32 says this layout prevents. operations.md:54 tells operators to alert on the bytes counter, which would actually alert on blob counts.\n\n🟡 `bug` services/proxy/src/sweep.rs:164: the comment says a symlink is \"counted at the size of the link\", but `fs::metadata` follows links; a hardlink-style store double-counts linked blobs at full size and evicts prematurely. `fs::symlink_metadata` is what the comment describes.\n\n🟡 `bug` services/proxy/src/main.rs:108: the comment (lines 101-102) claims the first tick is one interval away, but `tokio::time::interval`'s first tick completes immediately, so a sweep runs at startup — on a pre-populated store it evicts and clears `incoming` the moment the process boots, contrary to the stated intent.\n\n🟡 `bug` services/proxy/src/sweep.rs:137: when `remove_file` fails (line 126), the blob is still counted in `removed`/`bytes` and pushed to `gone`, so `forget` deletes index entries pointing at a blob still on disk and the recorded metrics claim bytes that were never reclaimed. Only count/push on a successful (or simulated) unlink.\n\n🟡 `bug` services/proxy/src/sweep.rs:90: `sweep` runs the entire synchronous `read_dir`/`unlink` walk inline on a tokio worker thread — in both the background task and the HTTP handler — blocking that worker for the whole pass (the module's own example is 65,000 directories). `spawn_blocking` would keep the scheduler serving requests during a long sweep.\n\n🔵 `bug` services/proxy/src/config.rs:131: `cache_min_age` is the only new setting with no validation, unlike its siblings `fetch_timeout` and `sweep_interval`; a `CAIRN_CACHE_MIN_AGE=0` typo silently disables the documented grace period, letting a store over its ceiling evict blobs seconds after they were fetched.","auth":{"mode":"api_key"},"effort":"high","elapsed_secs":421.952,"error":null,"error_kind":null,"instructions":[],"model":"z-ai/glm-5.3-flash","ok":true,"sandbox":{"backend":"macOS Seatbelt","denied_read_roots":[],"environment":["HOME","LANG","LC_ALL","PATH","TERM","TMPDIR"],"mode":"read-only","network":"denied","protected_write_roots":["/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/.git","/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/.afi","/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/.agents","/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/.codex","/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/AGENTS.md","/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/CLAUDE.md"],"readable_paths":["/"],"readable_roots":["/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee","/Users/bart.smykla@konghq.com/Projects/github.com/smykla-skalski/benchee/.git","/bin","/sbin","/usr/bin","/usr/sbin","/usr/lib","/usr/libexec","/usr/share","/System/Library","/Library/Apple","/Library/Filesystems/NetFSPlugins","/Library/Preferences","/private/etc","/private/var/db/timezone","/private/var/db/DarwinDirectory/local/recordStore.data","/private/var/select/developer_dir","/private/var/select/sh","/opt/homebrew/bin","/opt/homebrew/Cellar","/opt/homebrew/etc/gitconfig","/opt/homebrew/lib","/opt/homebrew/opt","/usr/local/bin","/Applications/Xcode.app/Contents/Developer","/Applications/Xcode.app/Contents","/Users/bart.smykla@konghq.com/.local/bin/afi"],"writable_roots":["/private/var/folders/d1/tvmyp5cs1gz38rltf390ddpw0000gn/T/afi-sandbox-yo3ezP"]},"schema_version":1,"source":"openrouter","sources":[{"auth":{"mode":"api_key"},"source":"openrouter","usage":{"cache_read_tokens":319104,"cache_write_tokens":0,"cost_usd":0.030604,"estimated_tokens":0,"input_tokens":45780,"output_tokens":775,"reasoning_tokens":28447,"requests":13,"total_tokens":394106}}],"system_prompt":{"file":null,"mode":"builtin"},"tools":["read_file","write_file","edit_file","list_dir","search_files","glob_files","run_bash","wait_background"],"usage":{"cache_read_tokens":319104,"cache_write_tokens":0,"cost_usd":0.030604,"estimated_tokens":0,"input_tokens":45780,"output_tokens":775,"reasoning_tokens":28447,"refused_by_approval":3,"refused_by_policy":0,"refused_tool_calls":3,"requests":13,"total_tokens":394106}}