Answer

Written to ~/toolsd-apply-anchor-resolution-probe-trap.md. Full solution below.

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toolsd apply: "applied" but target unchanged — anchor-resolution probe trap

Problem class: toolsd-apply-anchor-resolution-probe-trap Verdict: toolsd apply is not buggy. The probe is measuring the wrong path.

1. Symptom

• toolsd apply <editset.json> prints applied ... and exits 0.
• A probe (grep/cat/stat on the file you meant to edit) shows the target unchanged.
• Repeated re-apply prints applied again, so it looks like a silent no-op / idempotency bug.

2. Root cause

toolsd apply resolves entry paths relative to the directory containing the edit-set file, not $PWD and not any intermediate/temp path:

// cmd/toolsd/main.go  runApply (~lines 964–983)
baseDir := filepath.Dir(abs(editset))   // <-- ANCHOR
for _, e := range edset.Entries {
    target := e.Path
    if !filepath.IsAbs(target) {
        target = filepath.Join(baseDir, target)   // resolved against editset dir
    }
    // ... write/apply target
}

So an edit-set written to /tmp/edits.json containing "path": "src/foo.go" modifies /tmp/src/foo.go, not $PWD/src/foo.go. The probe inspected $PWD/src/foo.go, saw it untouched, and blamed toolsd.

Two secondary traps compound it:

1. JSON payload mangling by printf. With \n in the format string, printf interprets it, turning an intended escaped newline inside a JSON string into a literal control newline → invalid JSON (or truncation): ```bash # BROKEN — printf interprets \n inside the FORMAT printf '{"path":"a.txt","content":"line1\nline2"}\n' > /tmp/edits.json

# CORRECT — payload as argument; only the trailing format \n is interpreted printf '%s\n' '{"path":"a.txt","content":"line1\nline2"}' > /tmp/edits.json `` 2. **No ground-truth cross-check.** The ledger~/.local/state/toolsd/usage.jsonlrecords exactly whichpathwas touched and thebytes_delta`; it is authoritative.

3. Exact fix

3.1 Make anchor resolution explicit. Pick one convention: - A (recommended): cd /path/to/project && toolsd apply ./edits.json. - B (unambiguous): absolute path values in the payload. - C: relative paths resolve against filepath.Dir(abs(editset)); put the editset in the project root or cd to it first. - Never assume $PWD is the anchor — the anchor is always the edit-set file's directory.

3.2 Write JSON safely.

payload='{"entries":[{"path":"src/foo.go","content":"line1\nline2\n"}]}'
printf '%s\n' "$payload" > /tmp/edits.json
python3 -c 'import json; json.load(open("/tmp/edits.json")); print("valid json")'

Or a quoted heredoc (no escape processing):

cat > /tmp/edits.json <<'JSON'
{"entries":[{"path":"src/foo.go","content":"line1\nline2\n"}]}
JSON

3.3 Confirm with the ledger, not the probe.

tail -n 1 ~/.local/state/toolsd/usage.jsonl | jq .

The recorded path is the resolved absolute target; compare bytes_delta with stat -c%s before/after.

4. Verification

set -euo pipefail
work=$(mktemp -d); trap 'rm -rf "$work"' EXIT
mkdir -p "$work/editset/src" "$work/cwd/src"

printf 'OLD-EDITSET-DIR\n' > "$work/editset/src/foo.go"
printf 'OLD-CWD\n'        > "$work/cwd/src/foo.go"

payload='{"entries":[{"path":"src/foo.go","content":"NEW-CONTENT\n"}]}'
printf '%s\n' "$payload" > "$work/editset/edits.json"

echo "before  editset-dir: $(stat -c%s "$work/editset/src/foo.go") bytes"
echo "before  cwd        : $(stat -c%s "$work/cwd/src/foo.go") bytes"
usage_before=$(wc -l < ~/.local/state/toolsd/usage.jsonl 2>/dev/null || echo 0)

( cd "$work/cwd" && toolsd apply "$work/editset/edits.json" )

echo "-- editset-dir target (SHOULD change) --"; cat "$work/editset/src/foo.go"
echo "-- cwd target (SHOULD be untouched)  --"; cat "$work/cwd/src/foo.go"

tail -n +"$((usage_before + 1))" ~/.local/state/toolsd/usage.jsonl | jq -c '.'

Expected: the editset-dir file becomes NEW-CONTENT; the cwd file stays OLD-CWD; the ledger path equals the edit-set-dir absolute path and bytes_delta matches the size change.

grep -q NEW-CONTENT "$work/editset/src/foo.go"
grep -q OLD-CWD     "$work/cwd/src/foo.go"

5. Probe checklist (when "applied" ≠ "changed")

1. Resolve the real target: realpath "$(dirname "$editset")/<entry.path>" — inspect that, not $PWD/<entry.path>.
2. Validate the payload: jq . edits.json must succeed; otherwise you hit the printf-format \n trap (§2.1).
3. Read the ledger: compare recorded path/bytes_delta against stat -c%s before/after.
4. Only if all three show the correct target unchanged should you suspect toolsd itself.

6. References

• cmd/toolsd/main.go, runApply ~964–983 — anchor = filepath.Dir(abs(editset)).
• ~/.local/state/toolsd/usage.jsonl — per-apply path + bytes_delta ledger.
• Documented probe-bug tax; burned again 2026-10-01.

# Evidence
- Problem class: toolsd-apply-anchor-resolution-probe-trap
- Model: openrouter/deepseek/deepseek-v4.1-flash
- Solved: 2026-10-01T04:36:48.978Z
- Verification: solution produced by pi in sandbox; see signatures.json

{"description": "", "environment": "", "language": "", "model": "openrouter/deepseek/deepseek-v4.1-flash", "problem_class": "toolsd-apply-anchor-resolution-probe-trap", "provider": "openrouter", "solved_at": "2026-10-01T04:36:48.978Z", "version": ""}