[taylorg009]

Two Windows problems found while chasing a windows-release flake in cgraph_daemon_server_test ("incremental state re-persisted to graph.json"). Evidence comes from a diagnostic branch (#211, to be closed) that repeated the test on the Windows runners with timing and Restart Manager logging.

1. The daemon stopped on a file Windows reports as access denied (product bug)

std::filesystem::exists(path) throws when the path cannot be stat'ed, and Windows reports a file that is being replaced (an editor's save) as "Access is denied". Four call sites used the throwing form:

• file_cache.cpp classify_cached_file and semantic_chunk_plan.cpp is_valid_cached_record: these run on the enrichment worker. In diag: Windows persist retry timing (do not merge) #211 the daemon stopped with enrichment refresh failed: std::filesystem::filesystem_error: exists: Access is denied.: "...\docs\guide.md". Since fix(cli): exit 1 instead of aborting on uncaught filesystem errors #179 that is a clean exit 1; before fix(cli): exit 1 instead of aborting on uncaught filesystem errors #179 it was std::terminate. In the test it showed up as a 600 s hang, because the test kept waiting on a daemon that had exited.
• incremental_update.cpp (two calls): these run on the serve loop for every watcher event, which is exactly when a file is mid-save.

All four now use the error_code overload. A file that cannot be checked counts as absent for that pass, as the neighbouring file_size/last_write_time checks already treat it, and the watcher reports it again once it is written.

Tests: file_cache_test and incremental_update_test reproduce the throw on POSIX with an unsearchable parent directory (exists throws status: Permission denied there). Both fail without the source change and pass with it.

2. The flake itself was the test starving the daemon's replace (test only)

try_write_file_atomically already retries MoveFileExW for 10 s while the target is held open. #211 showed the replace denied for longer than that, and Restart Manager named only the test process as the holder. The test polled graph.json and the stat index with std::ifstream every 20 ms, and MSVC opens without FILE_SHARE_DELETE. The test now reads those files through read_shared, which on Windows opens with FILE_SHARE_DELETE so the replace goes through mid-read. POSIX is unchanged.

Verification

• Local (Linux, default preset): 104/104 tests; cgraph_daemon_server_test 3 repeats green.
• Windows, diag: Windows persist retry timing (do not merge) #211 (same two changes, run 39527312675 at 865eab3): cgraph_daemon_server_test passed 40/40 on windows-default and 40/40 on windows-release, with 0 denied replaces. Before the changes, the same harness failed on windows-release in both rounds (round 1 also hung on windows-default when the daemon stopped on exists: Access is denied).
• CI on this PR (30c58fe): 12/12 green, including both Windows jobs.
• Review follow-up (30c58fe): a failed exists() now classifies as Unreadable, not Deleted, so a full rescan keeps a verified file's nodes. incremental_update_test indexes the file before locking it; a mutant that erases indexed files on a failed check fails it.

🤖 Generated with Claude Code

[github-actions]

PR brief: 0 agent commits · 12 of 110 test files reach this diff

Run at least these. Selection is a safe superset; it never marks a test safe to skip.

Summary	PR #212 at 30c58fe
Changed	6 files: 6 mapped to 7 symbols
Tests reached	12 of 110 ▮▮▯▯▯▯▯▯▯▯▯▯▯▯▯▯▯▯▯▯ 11% of the suite
Downstream code	5 files, 41 dependents
Intent	no checkpoints on this branch (3 commits)
Since push 903a881	1 new commit, 0 changed files, 0 tests reached
Compared against	base d0cbc70

What each commit did

Commit	Intent	Files	Reaches	Ran before push
d0d9154 fix(daemon): do not stop on a file Windows reports as acces…	no checkpoint	5 files	5 files, 12 tests
903a881 test(daemon): read daemon-written files with FILE_SHARE_DEL…	no checkpoint	1 file	0 files, 1 test
30c58fe fix(file-cache): a failed exists() is Unreadable, not Delet…	no checkpoint	4 files	5 files, 12 tests

Claims checked

no checkpoint on this branch makes a claim the graph can check

What each changed file reaches

Changed file	Symbols touched	Reaches	Tests
file_cache.cpp	classify_cached_file	5 files	12
semantic_chunk_plan.cpp	is_valid_cached_record	4 files	7
incremental_update.cpp	apply_incremental_code_updates	2 files	6
tests/smoke/daemon_server_test.cpp	test code, selected directly		1
tests/smoke/file_cache_test.cpp	test code, selected directly		1
tests/smoke/incremental_update_test.cpp	test code, selected directly		1

Paths above are under src/engine/ unless shown in full.

Tests to run (12)

• tests/smoke/client_runtime_test.cpp
• tests/smoke/daemon_persistence_test.cpp
• tests/smoke/daemon_server_test.cpp
• tests/smoke/file_cache_test.cpp
• tests/smoke/host_surface_integration_test.cpp
• tests/smoke/incremental_dedup_test.cpp
• tests/smoke/incremental_rescan_test.cpp
• tests/smoke/incremental_update_test.cpp
• tests/smoke/index_persistence_test.cpp
• tests/smoke/semantic_chunk_plan_test.cpp
• tests/smoke/semantic_ingest_test.cpp
• tests/smoke/semantic_orchestration_test.cpp

Blast radius by changed file: 41 dependents

• file_cache.cpp reaches main, run, run_enrich_plan (src/cli/main.cpp), main, run (src/daemon/main.cpp), run_daemon_server (daemon_server.cpp), tree_matches_manifest (index_persistence.cpp), plan_enrichment (semantic_orchestration.cpp)
• semantic_chunk_plan.cpp reaches main, run, run_enrich_plan (src/cli/main.cpp), main, run (src/daemon/main.cpp), run_daemon_server (daemon_server.cpp), plan_enrichment (semantic_orchestration.cpp)
• incremental_update.cpp reaches main, run (src/daemon/main.cpp), run_daemon_server (daemon_server.cpp)

_{blastline 0.13.0. Selection is advisory unless your workflow gates on it. How selection works. Graph 307ba96. Intent: 0 of 3 commits. Not checked: symbol changes: no --change-context given.}

[tgod009]

Independent review: NON-BLOCKING, ready to merge.

• All four exists() calls on the enrichment-worker and serve-loop paths use the error_code overload; the remaining throwing calls on those paths touch only the project root, never a file being saved.
• Incremental path: an indexed file whose check fails is kept and republished, not erased; a never-indexed file is skipped. The watcher re-reports it when its token changes.
• The review's main SHOULD (a full rescan dropping a file whose check failed) is fixed in 30c58fe (Unreadable keeps the verified entry), and the incremental test now covers the indexed-file branch (a mutant that erases fails it).
• read_shared closes its handle before returning, so removing persisted.close() is safe.

Windows evidence: #211 ran cgraph_daemon_server_test 40/40 on each Windows job with 0 denied replaces; CI on 30c58fe is 12/12 green.