Cross-Code Review: B-5 macOS NFS Detection `df -P` Fallback Verification & Closure

Job ID: f20724aa
Reviewer: cline (session: herdr:canary-projects-multi-agent-mux-creator-cline)
Task: Review and resolve B-5 backlog item — validate macOS NFS detection via df -P fallback in _check_is_nfs, close B-5 in IMPROVEMENTS.md, document in VERSIONS.md, run full tests for 100% PASS.
Date: 2026-08-17
Base Commit: ac97550
Changeset: 2 files modified (IMPROVEMENTS.md, VERSIONS.md) — documentation-only, no production code changed.

1. Changeset Overview

1.1 Scope

File	Status	Lines Changed	Nature
`IMPROVEMENTS.md`	Modified (tracked)	+12 / -25	Backlog documentation: B-5 closure + stale-entry cleanup
`VERSIONS.md`	Modified (tracked)	+3 / -0	Version history: B-5 closure entry under v2.0.0

No production code modified. The df -P fallback in lib.sh:1184-1186 and the unit test test_stop_check_is_nfs_local in tests/test_tier1_unit.py:126-130 already existed in prior commits (ea36e81 and earlier). This changeset is a formal documentation closure of B-5.

1.2 IMPROVEMENTS.md Changes

Header (line 3): Updated date to mention B-5 closure.
Header (line 5): Open count 5건 → 4건 (아키텍처 1건, 엣지케이스 4→3건).
Header (line 6): Completed count 20건 → 21건; B-5 added to the completed ID list.
Section 2 (line 70): Header 4건 → 3건.
Section 2: Removed B-5 (newly closed), B-6 (already completed, stale entry), B-12 (already completed, stale entry), and B-8 (already completed, stale entry — confirmed completed via roadmap row P1-2 at line 145).
Section 5 (line 92): Header 20건 → 21건; new B-5 detailed entry added at line 94-95.
Roadmap (line 245): Row 종결 권고 → 종결 with test reference.

1.3 VERSIONS.md Changes

2. Review Perspectives

2.1 Lint (린트) — ✅ PASS

Check	Method	Result
`lib.sh` syntax (unchanged, but referenced)	`bash -n lib.sh`	✅ OK
IMPROVEMENTS.md header count consistency	`grep` header vs section counts	✅ 4건 = 1 arch + 3 edge
Section 2 item count	`grep '^### \\'` in lines 70-82	✅ 3 items (B-13, B-9, B-10) = "3건"
Section 5 item count	`grep '^### \\'` in lines 92-250	✅ 21 items = "21건"
B-5 absent from section 2	`grep 'B-5'` in lines 70-82	✅ NOT FOUND (correct)
B-5 present in section 5	`grep 'B-5'` in lines 92-250	✅ Found (line 94 + roadmap line 245)
Line reference `lib.sh:1181-1192`	`sed -n '1181,1192p'`	✅ `_check_is_nfs()` starts at 1181
Test name reference	`test_tier1_unit.py::test_stop_check_is_nfs_local`	✅ Exists at line 126
VERSIONS.md entry formatting	`sed -n '71,73p'`	✅ Well-formed under v2.0.0

2.2 Operability (동작성) — ✅ PASS

Check	Method	Result
`df --output=target` fails on macOS	`df --output=target . 2>/tmp/df_err.txt; echo rc=$?`	✅ rc=64 — "df: unrecognized option `--output=target'" (confirms original B-5 issue)
`df -P` fallback works	`df -P . 2>/dev/null \| tail -1 \| awk '{print $6}'`	✅ Returns `/System/Volumes/Data`
mount grep evaluates correctly	`mount \| grep -i -q -E "$mountpoint.*(nfs\|cifs\|smb\|sshfs)"`	✅ IS_NFS=no (local filesystem, correct)
Unit test `test_stop_check_is_nfs_local`	`pytest tests/test_tier1_unit.py::test_stop_check_is_nfs_local -v`	✅ PASSED (0.08s) — asserts rc=1 for local non-NFS
Full regression suite	`pytest tests/ -q --tb=short` (background)	✅ 263 passed in 391.80s (0:06:31) — 100% PASS

Runtime verification was performed on this actual macOS machine (darwin platform), confirming:

The GNU-only df --output=target flag fails with rc=64.
The POSIX df -P fallback at lib.sh:1186 correctly resolves the mountpoint.
The mount | grep check at lib.sh:1188 correctly evaluates the filesystem type.
The unit test validates local non-NFS detection (rc=1).

2.3 Loss (유실) — ✅ PASS

Check	Method	Result
B-5 fully removed from open section 2	`grep 'B-5'` in section 2	✅ No B-5 entry remains in open section
B-5 in completed list (header)	`grep 'B-5'` in line 6	✅ B-5 present in 21-item completed list
B-5 detailed entry in section 5	`sed -n '92,95p'`	✅ Full entry with line refs and test name
B-11 (split-off residual) preserved	`grep 'B-11'`	✅ Documented at line 313 (mount-point ERE interpolation recommendation)
Roadmap row updated	`grep -n 'B-5'` at line 245	✅ "종결" with `test_stop_check_is_nfs_local` reference
VERSIONS.md entry added	`sed -n '71,73p'`	✅ Entry 6 under v2.0.0
No production code lost	`git diff --stat`	✅ Only 2 doc files changed (12 insertions, 25 deletions)
Stale entries cleaned (B-6, B-8, B-12)	Section 2 grep	✅ All three were already completed; removal is correct cleanup

3. Worker Report Cross-Check

The Worker (agy, Job 21c6a451) reported:

df --output=target fails on macOS (empty output) → ✅ Confirmed (rc=64)
df -P fallback returns /System/Volumes/Data → ✅ Confirmed on this machine
Unit test test_stop_check_is_nfs_local exits with code 1 for local → ✅ Confirmed PASS
IMPROVEMENTS.md counts updated (4 open, 21 completed) → ✅ Confirmed
VERSIONS.md entry added → ✅ Confirmed
Worker ran 112/112 subset tests → ✅ Reviewer ran full 263/263 (superset)

All worker claims are independently verified and accurate.

4. Minor Non-Blocking Observations

Pre-existing stale conclusion text (line 317): "남은 백로그 항목(아키텍처 2건, 엣지케이스 6건, 오케스트레이션 1건, 레거시 잔재 3건 — 총 12건)" — this conclusion-section text does not match the current header (4건). Not introduced by this changeset; pre-existing. No action required for B-5 scope.
B-11 not formally tracked as an open item: The B-5 residual (mount-point ERE interpolation without escaping) is documented as a "split-off recommendation" at line 313 but has not been added to section 2 as a formal tracked open item. This is a pre-existing situation (the old B-5 entry also only mentioned B-11 as a recommendation). Consider formalizing B-11 as a tracked item in a future task, but this is outside B-5's scope.
Documentation-only changeset: No production code was changed. The df -P fallback logic and unit test already existed. This is the correct approach — B-5 was a verification/closure task, not an implementation task.

5. Verdict

The B-5 backlog item has been correctly verified and closed:

The df -P POSIX fallback in _check_is_nfs (lib.sh:1186) works correctly on macOS, as confirmed by live runtime measurement on this machine (rc=64 for df --output=target, /System/Volumes/Data via df -P).
The unit test test_stop_check_is_nfs_local validates the local non-NFS path (rc=1).
B-5 is properly moved from open section 2 to completed section 5 in IMPROVEMENTS.md with accurate line references and test names.
VERSIONS.md documents the closure under v2.0.0.
All counts are internally consistent (4 open, 21 completed).
The full regression suite passes: 263/263 PASS (100%) in 391.80s.
No production code was modified — the changeset is purely documentation.

[VERDICT: PASS]

7.4 KiB Raw Blame History

Cross-Code Review: B-5 macOS NFS Detection df -P Fallback Verification & Closure