machine-specific-paths at v0.19.0: five classes fire on prose, published changelog history, and fixtures whose assertion subject is the path

[kyle-sexton]

Repinning claude-code-plugins from c2654182 to v0.19.0 (85e140fa2fe9ebe96c41156055e7676de208090a) turned the machine-specific-paths lane red with 40 hits across 22 files and all five detection classes. On inspection, none of them is a machine-specific path that a contributor accidentally committed. Every one is prose describing the path form, or a test fixture whose assertion subject is the path.

Observed on melodic-software/claude-code-plugins run 33808374809, where all five classes fired at once.

What the patterns are matching

machine-path-patterns.sh's own header states the design intent this contradicts:

Excluding whitespace from the class is what makes dropping the separator prose-safe: a phrase like /Users/ for details cannot match because at least one non-space child character must follow the root.

That reasoning holds only for a root followed by a space. It does not hold for the shape prose actually uses, which is a root followed by a concrete example segment, /Users/alice, C:/Users/..., D:\repos\..., inside a sentence explaining what the code parses. The child-segment class admits ., so even the ellipsis form C:/Users/... matches. Fixtures are not addressed by the header at all.

The 40 hits, grouped by class

Windows user path

plugins/ai-slop/skills/audit/scripts/detect.sh:474
plugins/claude-ops/skills/plugins/scripts/fleet-state.sh:558
plugins/machine-health/skills/audit/tests/windows/lib/ConvertFrom-Jsonc.Tests.ps1:84
plugins/machine-health/skills/audit/tests/windows/lib/ConvertFrom-Jsonc.Tests.ps1:86
plugins/source-control/skills/pull-request/scripts/fetch-annotations.test.sh:21
plugins/source-control/skills/pull-request/scripts/fetch-failed-logs.test.sh:21

macOS user path

plugins/claude-config/CHANGELOG.md:1202
plugins/disk-hygiene/skills/clean/scripts/<the module under test>:1159
plugins/disk-hygiene/skills/clean/scripts/test_<same module>:2358
plugins/guardrails/CHANGELOG.md:3643

Linux user path

plugins/disk-hygiene/skills/clean/evals/evals.json:19
plugins/disk-hygiene/skills/clean/scripts/test_<same module>:2372
plugins/disk-hygiene/skills/clean/scripts/test_<same module>:2375

Windows repo path

plugins/claude-config/CHANGELOG.md:1508
plugins/claude-config/lib/state-key.test.sh:121
plugins/claude-ops/skills/plugins/context/gotchas.md:37
plugins/disk-hygiene/skills/clean/scripts/test_guard_launch_monitor.py:81
plugins/guardrails/CHANGELOG.md:3944
plugins/guardrails/CHANGELOG.md:3968
plugins/guardrails/CHANGELOG.md:3969
plugins/knowledge/skills/video-digest/extraction/lib/run-args.test.js:149
plugins/knowledge/skills/video-digest/extraction/lib/run-args.test.js:150
plugins/markdown-format/hooks/markdown-format.sh:209
plugins/repo-fleet-hygiene/skills/audit/scripts/audit-fleet.sh:1867
plugins/repo-hygiene/CHANGELOG.md:521
plugins/repo-hygiene/skills/clean/context/clean-batch.md:65
plugins/repo-hygiene/skills/clean/context/clean-batch.md:66
plugins/repo-hygiene/skills/clean/scripts/git-tree-reset-batch.test.sh:92
plugins/repo-hygiene/skills/clean/scripts/lib/batch-common.sh:17
plugins/repo-hygiene/skills/clean/scripts/lib/batch-common.sh:18
plugins/session-flow/skills/retro/scripts/test_parse_transcript.py:183
plugins/session-flow/skills/retro/scripts/test_parse_transcript.py:197
plugins/source-control/scripts/landed-work.sh:106

Escaped Windows repo path

plugins/disk-hygiene/skills/clean/scripts/test_guard_launch_monitor.py:81
plugins/knowledge/skills/video-digest/extraction/lib/run-args.test.js:149
plugins/knowledge/skills/video-digest/extraction/lib/run-args.test.js:150
plugins/session-flow/skills/retro/scripts/test_parse_transcript.py:183
plugins/session-flow/skills/retro/scripts/test_parse_transcript.py:197

Two disk-hygiene paths above are written with placeholders because quoting them verbatim trips that plugin's own guardrail hook.

Three categories that cannot be reworded

Published CHANGELOG history. Four hits are in CHANGELOG.md files, across three plugins. These are released entries. Rewording them edits history that already shipped to consumers, and several of them are describing a previous fix to this very detector: guardrails/CHANGELOG.md:3968 documents that the drive-letter-anchored pattern used to match only X:\repos\…, and it necessarily quotes the forms it then began catching.

Fixtures whose assertion subject is the path. Path("/Users/alice") in a case-folding test; "C:\\Projects\\..." in a cwd-parsing fixture; D:\\repos\\knowledge-corpus in an environment-variable expansion test; a Pester case asserting a JSONC reader preserves an escaped path. Changing the literal changes what the test proves, so the remedy is not available at any price.

Prose naming the form the surrounding code parses. A comment saying git answers C:/Users/... on Git Bash, sitting directly above the code that handles that answer. Replacing the example with a placeholder makes the comment describe nothing.

What we did downstream, and what we would like

We held machine-specific-paths alone at c2654182 while every other reference in that workflow moved to v0.19.0, tracked in melodic-software/claude-code-plugins#3699. That leaves a deliberate second SHA in a file we had just unified, which we would rather not keep.

No fix design proposed beyond the shape of the need: placeholder forms and fixture contexts need to be recognised, or opt-out-able per phrase rather than per file. A file-level exclude is the only lever the action offers today, and excluding twenty-two files to silence forty phrases removes ten plugins from the scan entirely, which costs more than the finding is worth.

[kyle-sexton]

This was generated by AI during triage.

Triage lane claim. Instance vm-triage-202609050304, lane triage, lease expires 2026-09-05T04:11:00Z.

Raw intake picked up for classification and briefing. No code changes will be made from this lane. The seam claim (/work-items:track start) was unavailable in this session — its GraphQL path is not served here — so this marker comment is the claim of record.

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Generated by Claude Code

[kyle-sexton]

This was generated by AI during triage.

Triage (autonomous lane). Claim released at the end of this comment.

1. The false-positive claim is VERIFIED

Reproduced independently by sourcing the pattern bodies out of .github/actions/machine-specific-paths/machine-path-patterns.sh and running them against a melodic-software/claude-code-plugins checkout. Line numbers below are at that repo's current main (5f5665ee), so they drift a few lines from the v0.19.0 numbers in the issue body; the hits themselves are the same ones.

Sampled across three of the five classes, every hit is prose, a comment, a fixture, or released changelog text. None is a committed machine-specific path.

Hit (at main)	Class	What it actually is
ai-slop/.../detect.sh:474	Windows user	comment: git answers `C:/Users/...` for the same
claude-ops/.../fleet-state.sh:920	Windows user	comment: installLocation is recorded in native form on Windows (C:\Users\...)
source-control/.../fetch-annotations.test.sh:23	Windows user	comment describing the accepted path forms
claude-ops/.../context/gotchas.md:37	Windows repo	prose: stores `projectPath` in native Windows form (`D:\repos\...`)
repo-hygiene/.../lib/batch-common.sh:22-23	Windows repo	comment contrasting D:\repos\... against D:/repos/...
knowledge/.../run-args.test.js:149-150	Windows repo + escaped	fixture: the literal IS the assertion subject
session-flow/.../test_parse_transcript.py:182,196	Windows repo + escaped	fixture: "cwd": "C:\\Projects\\example"
markdown-format/hooks/markdown-format.sh:209	Windows repo	comment about JSON-escaped arrival
claude-config/CHANGELOG.md:1211,1224	macOS user	released entries describing a previous fix to this detector

2. Root cause, stated precisely

machine-path-patterns.sh's header justifies prose-safety like this:

a phrase like /Users/ for details cannot match because at least one non-space child character must follow the root.

That argument only covers root followed by whitespace. It does not cover the shape prose actually uses: root followed by a concrete example segment inside a sentence. And the child-segment class [^\\$%<{~"[:space:]/] admits ., so even the deliberately-abstract ellipsis form C:/Users/... satisfies "at least one non-space child character". The ellipsis, which authors reach for precisely to avoid naming a real machine, is what trips the detector.

Fixtures are not addressed by the header's reasoning at all.

3. Lever inventory (confirms the issue's "only lever is file-level exclude")

• check-machine-specific-paths.sh is 62 lines and contains no suppression, exemption, or marker handling of any kind.
• action.yml exposes exactly two inputs: paths and exclude, both git pathspec-level.

So the issue is correct that silencing 40 phrases today costs 22 files, which removes ten plugins from the scan.

4. Why this is gated rather than agent-ready

This is not a pattern tweak. It requires inventing a suppression contract for a detector that every consumer repo runs, and the invention has a real failure mode in both directions: too loose and a genuine committed machine path walks through a marker; too strict and the three unfixable categories in the issue body stay red forever. That design decision belongs to a human. Labels set: work-class: structural, status: needs-decision, needs-human, priority: medium; priority: needs-triage removed.

5. Brief a cold agent can execute once the design is chosen

Design options to decide between (this is the human's call):

1. Line-level opt-out marker in the driver (for example a trailing machine-path-allow comment, or a preceding marker line). Cheapest, and it is per-phrase rather than per-file, which is exactly the granularity the issue asks for. Does not help CHANGELOG history, which nobody wants to edit.
2. Path-shape allowlist: treat placeholder forms (..., <user>, alice, example) as non-machine-specific by narrowing the child-segment class or adding a negative post-filter. Fixes prose and the ellipsis form without touching any file.
3. Context exemption for known-inert trees: CHANGELOG.md and test/fixture paths. Blunt, but it is the only option that covers released history without rewriting it.

Options 2 and 3 together cover all three "cannot be reworded" categories with no per-line annotation burden. That is the combination worth pricing first.

Where the work lands: .github/actions/machine-specific-paths/ (machine-path-patterns.sh for option 2, check-machine-specific-paths.sh for options 1 and 3, action.yml if a new input is introduced).

Acceptance test, and the precedent to copy: the sibling comment-hygiene action ships superset-test.sh with assert_caught 'TODO marker' '# TODO refactor this' style cases. machine-specific-paths has no equivalent fixture file at all, which is why this regression shipped. Add one, and make it assert both directions:

• MUST still catch: a real committed absolute path such as C:\Users\someone\project, /Users/someone/project, /home/someone/project, D:\repos\thing, and the JSON-escaped and 8.3 short-name variants the header says were deliberately added.
• MUST NOT catch: C:/Users/..., D:\repos\..., /Users/alice inside a sentence, and a fixture literal whose surrounding line is an assertion.

Definition of done: the machine-specific-paths lane is green on claude-code-plugins at v0.19.0 or later with zero file-level excludes added, and melodic-software/claude-code-plugins#3699 can drop the held-back c2654182 pin so that workflow carries a single SHA again.

Must not regress: POSIX ERE only, no grep -P (macOS BSD grep lacks it, and the header calls this out explicitly). The detector's existing widenings for JSON-escaped separators and 8.3 short names must survive.

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Triage lane instance vm-triage-202609050304. Claim released; no code changed, no PR opened.

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Generated by Claude Code