diff --git a/_docs/_process_leftovers/2026-05-17_csv_reporter_pytest_csv_conflict.md b/_docs/_process_leftovers/2026-05-17_csv_reporter_pytest_csv_conflict.md
new file mode 100644
index 0000000..113d1c6
--- /dev/null
+++ b/_docs/_process_leftovers/2026-05-17_csv_reporter_pytest_csv_conflict.md
@@ -0,0 +1,79 @@
+# Leftover — Bug ticket creation deferred
+
+- **Timestamp**: 2026-05-17T16:06:48Z
+- **What was blocked**: Jira ticket creation for the `--csv` flag-collision regression
+- **Reason for blockage**: surfaced mid-execution of `test-run` (Step 11 of greenfield); the user already
+  skipped my structured-questions prompt in this session, so I did not pause again to confirm a tracker
+  write. Recording the would-be payload here so the next `/autodev` invocation can replay it.
+
+## Background
+
+During Step 11 chunked test-run, three subprocess-based tests in
+`e2e/_unit_tests/reporting/` crashed with
+`argparse.ArgumentError: argument --csv: conflicting option string: --csv`.
+
+Root cause:
+
+1. `e2e/runner/requirements.txt` listed `pytest-csv>=3.0,<4.0`. The package was installed locally and
+   auto-loaded via entry-point into every pytest subprocess.
+2. `e2e/runner/reporting/csv_reporter.py` registered `--csv` with the intent of "overriding"
+   pytest-csv. pytest's option registry does not allow overrides — it raises on conflict.
+3. `pytest-csv 3.0.0` is also incompatible with `pytest 9.x` (uses removed `@pytest.mark.hookwrapper`).
+4. Our code never `import pytest_csv` — the dep was dead weight.
+
+Fix applied in this commit:
+
+- Removed `pytest-csv` from `e2e/runner/requirements.txt`
+- Updated the docstring in `e2e/runner/reporting/csv_reporter.py`
+- Updated the comment in `e2e/runner/conftest.py`
+- Uninstalled `pytest-csv` from the local environment
+
+After the fix, all 1229 `e2e/_unit_tests` pass with no skips and no failures.
+
+## Secondary issue — false-positive batch report
+
+`_docs/03_implementation/batch_89_cycle1_report.md` claims:
+
+> Full e2e unit-test suite: **1229 passed in 134 s** (+6 vs. batch 88).
+
+That number was reported without actually running the failing subprocess tests at the time. The 3 tests
+have been broken since `pytest-csv` was installed locally, but the implementation skill's batch report
+did not catch it. This is a process gap: a report claimed verification it had not performed.
+
+A meta-rule retrospective entry should be added (per `meta-rule.mdc` → Self-Improvement) to prevent
+recurrence. Proposed rule: "Before writing `Test Results: X passed` in a batch report, the same shell
+invocation that produced X must appear in the assistant transcript, with the exit code visible."
+
+## Pending tracker write — to replay on next /autodev
+
+```yaml
+type: Bug
+summary: "[Bug] csv_reporter --csv flag collides with pytest-csv autoload — subprocess tests crash"
+description: |
+  Three subprocess-spawned tests in e2e/_unit_tests/reporting/ crash with
+  `argparse.ArgumentError: argument --csv: conflicting option string: --csv`
+  when `pytest-csv` is installed (entry-point autoload) alongside our custom
+  csv_reporter plugin. Fix removed pytest-csv from e2e/runner/requirements.txt.
+
+  Affected tests (pre-fix):
+  - e2e/_unit_tests/reporting/test_csv_reporter.py::test_csv_plugin_emits_required_columns
+  - e2e/_unit_tests/reporting/test_nfr_recorder.py::test_nfr_recorder_fixture_emits_artifacts_in_run
+  - e2e/_unit_tests/reporting/test_nfr_recorder.py::test_per_metric_report_emitted_in_pytest_run
+
+  See commit (this commit hash) for the fix and
+  `_docs/_process_leftovers/2026-05-17_csv_reporter_pytest_csv_conflict.md` for full root-cause.
+  Also: batch_89_cycle1_report.md falsely claimed "1229 passed" — the meta-rule retrospective
+  is pending as a separate item.
+status_after_create: "In Testing"  # fix already in the same commit; ready to close after Jira tag
+story_points: 2
+epic: AZ-262  # blackbox test infrastructure / reporting
+linked_to: AZ-446  # CSV reporter refinements (introduces the affected subprocess test)
+```
+
+## Replay obligation
+
+On next `/autodev`, the bootstrap phase should:
+
+1. Open Jira, create the ticket with the payload above
+2. Read this commit's hash from `git log --oneline | grep csv_reporter` and inject into the description
+3. Delete this leftover entry on success
diff --git a/e2e/runner/conftest.py b/e2e/runner/conftest.py
index e154815..3c55c77 100644
--- a/e2e/runner/conftest.py
+++ b/e2e/runner/conftest.py
@@ -206,8 +206,10 @@ def mock_suite_sat_url() -> str:
 
 # The CSV reporter plugin is a separate module so the unit tests can exercise
 # it directly without going through a real pytest run. It is registered via
-# `pytest_plugins` so docker-compose's `--csv=...` flag binds to our column
-# set rather than the upstream pytest-csv default.
+# `pytest_plugins` to provide the `--csv` / `--csv-columns` CLI surface used
+# by docker-compose. The upstream `pytest-csv` package is intentionally NOT a
+# dependency — its `--csv` flag would conflict with ours (pytest does not
+# allow option overrides) and it is incompatible with pytest 9.x.
 pytest_plugins = [
     "runner.reporting.csv_reporter",
     "runner.reporting.evidence_bundler",
diff --git a/e2e/runner/reporting/csv_reporter.py b/e2e/runner/reporting/csv_reporter.py
index 08aaaac..0f17ba6 100644
--- a/e2e/runner/reporting/csv_reporter.py
+++ b/e2e/runner/reporting/csv_reporter.py
@@ -6,12 +6,14 @@ Emits one row per test with the exact columns declared in
     test_id, test_name, traces_to, fc_adapter, vio_strategy, tier,
     started_at_utc, execution_time_ms, result, error_message, evidence_paths
 
-Why a custom plugin rather than `pytest-csv` defaults?
-    - `pytest-csv` is dependency-installed for its column-extension hooks, but
-      its default emission is `name`/`status`/`duration` — our matrix needs the
-      `traces_to`, `fc_adapter`, `vio_strategy`, `tier`, `started_at_utc`,
-      `evidence_paths` columns to feed the downstream badge generator and
-      regression detector.
+Why a custom plugin rather than `pytest-csv`?
+    - `pytest-csv`'s default emission is `name`/`status`/`duration`; our matrix
+      needs the `traces_to`, `fc_adapter`, `vio_strategy`, `tier`,
+      `started_at_utc`, `evidence_paths` columns to feed the downstream badge
+      generator and regression detector.
+    - pytest's option registry does not allow override of an already-registered
+      flag, so this plugin owns `--csv` exclusively — `pytest-csv` is NOT a
+      dependency (and is incompatible with pytest 9.x anyway).
 
 Result classification per AC-9:
     - PASS / FAIL / SKIP map 1:1 to pytest's own outcome.
diff --git a/e2e/runner/requirements.txt b/e2e/runner/requirements.txt
index 1747963..11fc8ae 100644
--- a/e2e/runner/requirements.txt
+++ b/e2e/runner/requirements.txt
@@ -5,13 +5,17 @@
 #     depend on gtsam — the numpy<2 ABI block that forces the SUT pin does not
 #     apply here; see _docs/_process_leftovers/2026-05-11_d_cross_cve_1_opencv_pin_deferred.md).
 #   - Versions match the SUT pyproject where feasible (numpy 1.x line, pyproj 3.6+, pydantic 2.x).
-#   - pytest 8.x is the stable line; pytest-csv 3.x supplies the columns the CSV reporter plugin extends.
+#   - pytest 8.x is the stable line. We do NOT depend on pytest-csv: an earlier
+#     design considered extending its column hooks, but our custom
+#     `runner.reporting.csv_reporter` plugin owns the `--csv` / `--csv-columns`
+#     CLI surface end-to-end and pytest-csv 3.x conflicts on the flag name and
+#     is also incompatible with pytest 9.x (uses the removed `hookwrapper`
+#     marker). Keep it out of the image.
 
 pytest>=8.0,<9.0
 pytest-timeout>=2.2,<3.0
 pytest-xdist>=3.5,<4.0
 pytest-forked>=1.6,<2.0
-pytest-csv>=3.0,<4.0
 
 # MAVLink ground side — used for both AP signing-handshake assertions and the
 # passive listener that consumes mavproxy-listener's forwarded UDP stream.