# Session Findings - 2026-03-28 22:34

## 1. Session Summary

**Work done**: Babysit-tp monitoring of testproject MR 2134 (shiftstack adoption full chain). Session included: RESUME from stale cron, status checks on a running single-stage build, user-requested full chain rerun (restore .zuul.yaml + push), then cron-triggered CHECK that detected the new buildset and fetched avg durations for all 7 chain stages.

**Zuul MCP tools used**:
- `mcp__zuul-sf__get_change_status` — 3 calls (initial check, verification, cron check)
- `mcp__zuul-sf__list_builds` — 6 parallel calls (avg duration fetching for chain stages)

**Other tools used for Zuul-adjacent work**: `glab api` (Bash) for GitLab bot notes and .zuul.yaml management — appropriate, not a Zuul gap.

**Overall friction level**: **Medium** — `list_builds` worked perfectly for batch avg computation. `get_change_status` returned correct data but the `not_in_pipeline` fallback path consistently lacks per-build timing fields, forcing manual computation.

---

## 2. Findings

### Finding 1: `get_change_status` `not_in_pipeline` + `IN_PROGRESS` lacks per-build timing (3 occurrences)

**Tool**: `mcp__zuul-sf__get_change_status`
**Parameters**: `change="2134", tenant="components-integration"` (all 3 calls)

**Response pattern** (same across all 3 calls — build was `not_in_pipeline` each time):
```json
{
  "status": "not_in_pipeline",
  "latest_buildset": {
    "result": "IN_PROGRESS",
    "first_build_start": "2026-03-28T18:52:52",
    "builds": [{
      "uuid": "594ec184...",
      "job": "shiftstack-rhel9-rhoso18.0-adoption-run-shiftstack-after",
      "result": "IN_PROGRESS",
      "project": "ci-framework/ci-framework-testproject",
      "change": 2134
    }]
  }
}
```

**What's missing**: Per-build objects lack `elapsed`, `start_time`, `estimated`, `report_url`, `stream_url`, `pre_fail`, `duration` — all fields that ARE present when the change is in-pipeline. Three consequences:

1. **Elapsed time**: Had to compute manually from `first_build_start` vs current time. This is approximate and wrong for multi-stage chains where builds start at different times (uses buildset start, not per-build start).
2. **Build URLs**: Had to hardcode `zuul_base + tenant + uuid` construction instead of using returned `report_url`.
3. **`pre_fail` unavailable**: Cannot detect early failures — must wait for bot note or poll again later.

**Severity**: **P2** — improvement. The tool works but requires manual workarounds for the most common babysit use case (monitoring a running build).

**Suggested fix**: When `not_in_pipeline` and buildset `result == "IN_PROGRESS"`, fetch per-build details from SQL (`GET /api/tenant/{tenant}/builds?buildset_uuid={uuid}`) and populate `start_time`, `duration` (if completed), `log_url`, and construct `report_url`. Fields like `elapsed`, `stream_url`, and `pre_fail` are pipeline-only (live state) and can legitimately be absent — but document this clearly in the response with a `"note": "Build executing outside pipeline — elapsed/pre_fail unavailable"`.

---

### Finding 2: 6 parallel `list_builds` calls needed for avg duration fetching

**Tool**: `mcp__zuul-sf__list_builds` (6 calls in parallel)
**Parameters**: Each with `job_name=<stage-name>, result="SUCCESS", limit=10`

**What happened**: To compute avg durations for a 7-stage chain (1 stage already cached), I needed 6 separate `list_builds` calls — one per job name. Each returned 6-10 builds with `duration` field. This worked correctly but is chatty.

**Example response** (deploy-infra):
```json
{
  "builds": [
    {"uuid": "3e23a578...", "job": "...-deploy-infra", "result": "SUCCESS",
     "duration": 2896.0, "project": "...", "change": 2134},
    ...
  ],
  "count": 10, "has_more": true
}
```

**Severity**: **P3** — polish. Each call was fast and returned exactly what was needed. The parallel execution made it efficient (~2s total). However, a batch endpoint would reduce 6 calls to 1.

**Suggested fix**: Add an optional `job_names` (list) parameter to `list_builds`, or a new `get_job_durations` tool that accepts multiple job names and returns `{job_name: {mean, median, min, max, count, durations[]}}`. This is a convenience optimization — the current approach works fine with parallel calls.

---

### Finding 3: `not_in_pipeline` status is ambiguous

**Tool**: `mcp__zuul-sf__get_change_status`
**Parameters**: same as Finding 1

**What was suboptimal**: All 3 calls returned `not_in_pipeline` even though the build was actively executing. This status is technically correct (the change item was dequeued from the pipeline after dispatch) but ambiguous — it could mean:
1. Build executing on a node (normal)
2. Build completed but SQL hasn't flushed yet
3. Build stuck/orphaned

The user challenged the reported status ("are you sure about this info????"), partly because the raw API state doesn't clearly communicate "running but dequeued."

**Severity**: **P3** — polish. Not broken, but confusing.

**Suggested fix**: When `not_in_pipeline` and latest buildset is `IN_PROGRESS`, set `status` to `"executing"` (or add `"status_detail": "executing_outside_pipeline"`) to distinguish from truly absent changes. Alternatively, add a human-readable `"note"` field.

---

### Finding 4: No chain/dependency awareness in responses

**Tool**: `mcp__zuul-sf__get_change_status`

**What was missing**: The response for buildset `9821f411` (full chain) only showed 1 build (`deploy-infra` IN_PROGRESS). The other 6 stages (deploy-ocp, deploy-osp, etc.) were absent — no QUEUED entries, no dependency graph. I had to reconstruct the full chain from `.zuul.yaml` knowledge and show QUEUED stages manually in the dashboard.

When a change IS in the pipeline, `get_change_status` returns all jobs (including queued ones) with their dependencies. But the `not_in_pipeline` fallback only returns builds that exist in SQL — queued jobs haven't been created as builds yet.

**Severity**: **P3** — polish. The babysit skill already knows the chain from `.zuul.yaml`, so it can fill in QUEUED stages. But it would be cleaner if the response included them.

**Suggested fix**: No easy fix — queued jobs only exist in the pipeline's in-memory state. Document that `not_in_pipeline` responses only contain builds that have actually started executing.

---

## 3. Missing Tools

No missing tools identified. All Zuul operations were achievable:
- Build status → `get_change_status` (with workarounds noted above)
- Avg durations → `list_builds` with `result=SUCCESS`
- Bot notes, .zuul.yaml management → GitLab API (correctly outside Zuul scope)

**Potential future need** (not hit this session):
- **Batch avg durations**: A `get_job_durations(job_names=[...])` tool would reduce 6 calls to 1 for the common "fetch chain timing" pattern. See Finding 2.

---

## 4. What Worked Well

### `list_builds` — excellent for batch avg computation
- 6 parallel calls, each returned in <1s
- `duration` field present on every build (no missing data)
- `count` and `has_more` pagination fields useful for knowing data completeness
- `result` filter worked perfectly — only SUCCESS builds returned
- Response was appropriately sized (10 builds × ~5 fields each)
- **Verdict**: This tool is solid. Don't change the response format.

### `get_change_status` — core detection works
- Correctly returned the latest buildset when change was `not_in_pipeline`
- `buildset_uuid` at the item level eliminated `list_buildsets` roundtrips
- `events` array provided useful trigger context (event type, timestamp, trigger description)
- `first_build_start` in the buildset enabled manual elapsed computation
- Bare change number (`2134`) worked correctly
- Deterministic responses — 2 identical calls returned identical results
- New buildset UUID detected correctly on 3rd call after `.zuul.yaml` push
- **Verdict**: Core functionality is reliable. The `not_in_pipeline` fallback path needs enrichment (Findings 1, 3, 4) but the tool is not broken.

### Parameter ergonomics
- `change` accepting bare numbers is intuitive
- `tenant` as optional with default is convenient
- `job_name`, `result`, `limit` on `list_builds` are clear and work as expected
- No parameter guessing was needed — names match expectations

---

## 5. Cross-Reference with Previous Session

This session's Finding 1 is the same issue as the [previous session report](session-findings-20260328-2223.md) Finding 1. The `not_in_pipeline` + `IN_PROGRESS` timing gap is the most consistent friction point across sessions. Promoting from P2 to **P1** based on recurrence — it affects every babysit check where the build happens to be dequeued from the pipeline (which is the majority of checks for long-running builds).
