fix: resolve conflicts for PR #415

Rebase onto current prgs/master and fix cleanup-mutations regex so
"Cleanup mutations: none" does not false-positive the proof checklist.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

final_report_validator.py

@@ -457,6 +457,40 @@ def _rule_reviewer_git_fetch_readonly(
     return []
 
 
+def _rule_reviewer_validation_failure_history(
+    report_text: str,
+    *,
+    validation_session: dict | None = None,
+) -> list[dict[str, str]]:
+    from reviewer_validation_failure_history import (
+        assess_validation_failure_history_report,
+    )
+
+    session = validation_session or {}
+    observed = session.get("observed_failures") or []
+    if not observed:
+        return []
+
+    result = assess_validation_failure_history_report(
+        report_text,
+        validation_session=session,
+    )
+    if result.get("proven"):
+        return []
+    severity = "block" if result.get("violations") else "downgrade"
+    return [
+        validator_finding(
+            "reviewer.validation_failure_history",
+            severity,
+            "Validation failure history",
+            reason,
+            result.get("safe_next_action")
+            or "document every observed validation failure before claiming pass",
+        )
+        for reason in (result.get("violations") or result.get("reasons") or ["incomplete"])
+    ]
+
+
 def _rule_reviewer_validation_command(report_text: str) -> list[dict[str, str]]:
     text = report_text or ""
     if not _BARE_PYTEST_RE.search(text):
@@ -879,6 +913,7 @@ _RULES_BY_TASK: dict[str, list[Callable[..., list[dict[str, str]]]]] = {
         _rule_reviewer_mutation_categories,
         _rule_reviewer_git_fetch_readonly,
         _rule_reviewer_validation_command,
+        _rule_reviewer_validation_failure_history,
         _rule_reviewer_validation_structured,
         _rule_reviewer_linked_issue,
         _rule_reviewer_baseline_on_failure,
@@ -986,6 +1021,7 @@ def assess_final_report_validator(
     local_edits: bool = False,
     issue_filing_lock: dict | None = None,
     session_pr_opened: bool = False,
+    validation_session: dict | None = None,
 ) -> dict[str, Any]:
     """Validate final-report text against task-specific proof rules (#327).
 
@@ -1041,6 +1077,7 @@ def assess_final_report_validator(
         "mutations_observed": mutations_observed,
         "local_edits": local_edits,
         "session_pr_opened": session_pr_opened,
+        "validation_session": validation_session,
     }
 
     for rule in _RULES_BY_TASK.get(normalized_kind, ()):

gitea_mcp_server.py

@@ -1245,7 +1245,7 @@ def gitea_create_pr(
     )
     if blocked:
         return blocked
-    verify_preflight_purity(remote)
+    verify_preflight_purity(remote, worktree_path=worktree_path)
     h, o, r = _resolve(remote, host, org, repo)
 
     # ── Issue Lock Validation (Issue #194 / #196) ──
@@ -3464,16 +3464,32 @@ def gitea_delete_branch(
         repo: Override the repository name.
 
     Returns:
-        dict with 'success' and 'message'.
+        dict with 'success' and 'message'; on a permission block,
+        'success'/'performed' False, 'reasons', and a structured
+        'permission_report' (#142) with no API call made.
     """
+    gate_reasons = _profile_operation_gate("gitea.branch.delete")
+    if gate_reasons:
+        return {
+            "success": False,
+            "performed": False,
+            "required_permission": "gitea.branch.delete",
+            "reasons": gate_reasons,
+            "permission_report": _permission_block_report("gitea.branch.delete"),
+        }
+
     verify_preflight_purity(remote)
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
     import urllib.parse
     encoded_branch = urllib.parse.quote(branch, safe="")
     url = f"{repo_api_url(h, o, r)}/branches/{encoded_branch}"
+    request_metadata = {
+        "branch": branch,
+        "required_permission": "gitea.branch.delete",
+    }
     with _audited("delete_branch", host=h, remote=remote, org=o, repo=r,
-                  target_branch=branch, request_metadata={"branch": branch}):
+                  target_branch=branch, request_metadata=request_metadata):
         api_request("DELETE", url, auth)
     return {"success": True, "message": f"Remote branch '{branch}' deleted."}
 
@@ -5510,6 +5526,7 @@ def gitea_validate_review_final_report(
     action_log: list[dict] | None = None,
     mutations_observed: bool = False,
     local_edits: bool = False,
+    validation_session: dict | None = None,
 ) -> dict:
     """Read-only: machine-validate reviewer final report schema before output (#391).
 
@@ -5527,6 +5544,7 @@ def gitea_validate_review_final_report(
         action_log=action_log,
         mutations_observed=mutations_observed,
         local_edits=local_edits,
+        validation_session=validation_session,
     )
 
 

post_merge_cleanup_proof.py

@@ -209,7 +209,7 @@ def assess_post_merge_cleanup_proof(
 
     if not remote_delete and not worktree_remove:
         cleanup_mutations = re.search(
-            r"cleanup mutations\s*:\s*(?!none\b)(.+)",
+            r"cleanup mutations\s*:\s*(?!none\b)\S",
             text,
             re.IGNORECASE,
         )

review_final_report_schema.py

@@ -301,6 +301,7 @@ def assess_review_final_report_schema(
     action_log: list[dict] | None = None,
     mutations_observed: bool = False,
     local_edits: bool = False,
+    validation_session: dict | None = None,
 ) -> dict[str, Any]:
     """Validate reviewer final report text before session completion (#391)."""
     base = assess_final_report_validator(
@@ -312,6 +313,7 @@ def assess_review_final_report_schema(
         action_log=action_log,
         mutations_observed=mutations_observed,
         local_edits=local_edits,
+        validation_session=validation_session,
     )
     extra: list[dict[str, str]] = []
     for rule in _SCHEMA_RULES:

review_proofs.py

@@ -5503,6 +5503,15 @@ def assess_validation_integrity_report(report_text, **kwargs):
     return _assess(report_text, **kwargs)
 
 
+def assess_validation_failure_history_report(report_text, **kwargs):
+    """#396: final reports must account for transient validation failures."""
+    from reviewer_validation_failure_history import (
+        assess_validation_failure_history_report as _assess,
+    )
+
+    return _assess(report_text, **kwargs)
+
+
 def assess_already_landed_classification_report(report_text, **kwargs):
     """#295: already-landed PRs are reconciliation-only, not review eligible."""
     from reviewer_already_landed_classification import (

reviewer_validation_failure_history.py

@@ -0,0 +1,198 @@
+"""Transient validation failure history verifier (#396).
+
+Reviewer sessions may observe validation failures that later pass on rerun.
+Final reports must document every failure observed during the session, not
+only the last passing result.
+"""
+
+from __future__ import annotations
+
+import re
+from typing import Any
+
+_SECTION_RE = re.compile(
+    r"validation failure history",
+    re.IGNORECASE,
+)
+_FAILURE_ENTRY_RE = re.compile(
+    r"(?:failure\s*(?:#|entry)?\s*\d+|validation failure)\s*:",
+    re.IGNORECASE,
+)
+_COMMAND_RE = re.compile(
+    r"(?:command|validation command)\s*:\s*(.+)",
+    re.IGNORECASE,
+)
+_FAILING_TEST_RE = re.compile(
+    r"(?:failing test|failure|error)\s*:\s*(.+)",
+    re.IGNORECASE,
+)
+_CAUSE_RE = re.compile(
+    r"(?:suspected cause|cause)\s*:\s*(.+)",
+    re.IGNORECASE,
+)
+_REPRODUCED_RE = re.compile(
+    r"(?:reproduced|reproduces)\s*:\s*(yes|no|unknown)",
+    re.IGNORECASE,
+)
+_BASELINE_RE = re.compile(
+    r"(?:on baseline master|baseline master|exists on baseline)\s*:\s*(yes|no|unknown|not checked)",
+    re.IGNORECASE,
+)
+_PR_CAUSED_RE = re.compile(
+    r"(?:pr[- ]caused|pr caused)\s*:\s*(yes|no|unknown|not proven)",
+    re.IGNORECASE,
+)
+_TRANSIENT_STATUS_RE = re.compile(
+    r"(?:passed after transient failure investigation|transient failure investigation)",
+    re.IGNORECASE,
+)
+_PLAIN_PASS_RE = re.compile(
+    r"validation\s*:\s*(?:pass|passed|strong|ok|green)\b",
+    re.IGNORECASE,
+)
+_ENV_CLEANUP_RE = re.compile(
+    r"(?:environmental cleanup|state cleaned|what changed between runs)\s*:",
+    re.IGNORECASE,
+)
+_UNKNOWN_CAUSE_RE = re.compile(
+    r"(?:suspected cause|cause)\s*:\s*(?:unknown|unexplained|not determined)",
+    re.IGNORECASE,
+)
+
+
+def _failure_documented_in_text(text: str, failure: dict[str, Any]) -> bool:
+    """Return True when *failure* appears documented in free-form report text."""
+    command = (failure.get("command") or "").strip()
+    failing = (failure.get("failing_test") or failure.get("error") or "").strip()
+    if command and command not in text:
+        return False
+    if failing and failing not in text:
+        return False
+    return bool(command or failing)
+
+
+def _section_has_structured_fields(text: str) -> bool:
+    if not _SECTION_RE.search(text):
+        return False
+    section_start = _SECTION_RE.search(text).start()
+    section = text[section_start:]
+    has_command = bool(_COMMAND_RE.search(section))
+    has_failure = bool(_FAILING_TEST_RE.search(section))
+    return has_command and has_failure
+
+
+def assess_validation_failure_history_report(
+    report_text: str,
+    *,
+    validation_session: dict | None = None,
+) -> dict[str, Any]:
+    """Require final reports to account for transient validation failures (#396)."""
+    text = report_text or ""
+    session = dict(validation_session or {})
+    reasons: list[str] = []
+    violations: list[str] = []
+
+    observed = list(session.get("observed_failures") or [])
+    final_status = (session.get("final_validation_status") or "").strip().lower()
+    cause_unknown = any(
+        (f.get("suspected_cause") or "").strip().lower() in {
+            "unknown", "unexplained", "not determined", ""
+        }
+        and not (f.get("pr_caused") or "").strip().lower() in {"yes", "no"}
+        for f in observed
+    ) or bool(session.get("cause_unknown"))
+
+    if not observed:
+        return {
+            "proven": True,
+            "block": False,
+            "reasons": [],
+            "violations": [],
+            "observed_failure_count": 0,
+            "safe_next_action": "proceed",
+        }
+
+    documented = _section_has_structured_fields(text)
+    if not documented:
+        for failure in observed:
+            if _failure_documented_in_text(text, failure):
+                documented = True
+                break
+
+    if not documented:
+        violations.append(
+            "session observed validation failure(s) but final report omits "
+            "Validation failure history"
+        )
+        reasons.append(
+            "every validation failure observed during the session must appear "
+            "in a Validation failure history section"
+        )
+
+    if documented and not _SECTION_RE.search(text):
+        reasons.append(
+            "failure details must appear under an explicit "
+            "'Validation failure history' heading"
+        )
+
+    for idx, failure in enumerate(observed, start=1):
+        prefix = f"failure #{idx}"
+        if not _failure_documented_in_text(text, failure) and documented:
+            reasons.append(
+                f"{prefix}: command and failing test/error not documented in report"
+            )
+        command = (failure.get("command") or "").strip()
+        failing = (failure.get("failing_test") or failure.get("error") or "").strip()
+        if not command:
+            reasons.append(f"{prefix}: missing command in session failure record")
+        if not failing:
+            reasons.append(
+                f"{prefix}: missing failing test or error in session failure record"
+            )
+
+    plain_pass = bool(_PLAIN_PASS_RE.search(text))
+    transient_wording = bool(_TRANSIENT_STATUS_RE.search(text))
+    final_passed = final_status in {
+        "passed",
+        "pass",
+        "passed_after_transient_failure_investigation",
+    }
+
+    if (final_passed or plain_pass) and observed:
+        if cause_unknown and not transient_wording:
+            violations.append(
+                "unknown transient failure cause cannot be erased as plain 'passed'"
+            )
+            reasons.append(
+                "when cause is unknown, use status "
+                "'passed after transient failure investigation'"
+            )
+        elif not transient_wording and final_status != "passed_after_transient_failure_investigation":
+            if not _ENV_CLEANUP_RE.search(text):
+                reasons.append(
+                    "later passing rerun must document what changed between runs "
+                    "or environmental cleanup performed"
+                )
+
+    if session.get("environmental_contamination") and not _ENV_CLEANUP_RE.search(text):
+        reasons.append(
+            "environmental /tmp state contamination must document cleanup or "
+            "what changed before the passing rerun"
+        )
+
+    proven = not reasons and not violations
+    return {
+        "proven": proven,
+        "block": bool(violations) or not proven,
+        "reasons": reasons,
+        "violations": violations,
+        "observed_failure_count": len(observed),
+        "documented": documented,
+        "safe_next_action": (
+            "add Validation failure history with command, failing test, cause, "
+            "reproduction, baseline comparison, and PR-caused evidence; use "
+            "'passed after transient failure investigation' when appropriate"
+            if not proven
+            else "proceed"
+        ),
+    }

skills/llm-project-workflow/workflows/review-merge-pr.md

@@ -538,6 +538,36 @@ Official validation integrity status must be one of:
 
 Do not invent a softer status.
 
+## 21A. Validation failure history rule
+
+Every validation failure observed during the review session must appear in the
+final report, even if a later rerun passes.
+
+Before claiming `Validation: passed`, list every failed validation command from
+the session under `Validation failure history`.
+
+For each failure, report:
+
+* command
+* failing test or error
+* suspected cause
+* whether it reproduced
+* whether it exists on baseline master
+* evidence for whether it is or is not PR-caused
+
+If a later rerun passes, also report:
+
+* what changed between runs
+* whether environmental state was cleaned (for example `/tmp` lock files)
+* why the pass is trustworthy
+
+If the cause is unknown, do not erase the earlier failure with plain
+`Validation: passed`. Use a status such as
+`passed after transient failure investigation`.
+
+`gitea_validate_review_final_report` rejects reports that omit known earlier
+validation failures when `validation_session.observed_failures` is supplied.
+
 ## 22. Baseline validation rule
 
 Do not run tests in the main checkout.
@@ -1130,6 +1160,7 @@ Controller Handoff:
 * Baseline worktree path:
 * Files reviewed:
 * Validation:
+* Validation failure history:
 * Official validation integrity status:
 * Terminal review mutation:
 * Review decision:

tests/test_delete_branch_capability.py

@@ -0,0 +1,217 @@
+"""Tests for gitea_delete_branch capability gate (Issue #408).
+
+``gitea_delete_branch`` requires the exact ``gitea.branch.delete`` operation:
+without it the delete fails closed (no preflight, no auth lookup, no API call,
+structured permission report). With it, deletion proceeds through existing
+preflight and audit unchanged.
+"""
+import json
+import os
+import sys
+import tempfile
+import unittest
+from unittest.mock import patch
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+import mcp_server
+from mcp_server import gitea_delete_branch
+
+FAKE_AUTH = "token fake"
+
+AUTHOR_NO_DELETE = {
+    "profile_name": "prgs-author",
+    "allowed_operations": [
+        "gitea.read", "gitea.pr.create", "gitea.pr.comment",
+        "gitea.branch.push", "gitea.issue.comment",
+    ],
+    "forbidden_operations": ["gitea.pr.approve", "gitea.pr.merge"],
+    "audit_label": "prgs-author",
+}
+
+AUTHOR_WITH_DELETE = {
+    "profile_name": "prgs-author-deleter",
+    "allowed_operations": AUTHOR_NO_DELETE["allowed_operations"] + [
+        "gitea.branch.delete",
+    ],
+    "forbidden_operations": ["gitea.pr.approve", "gitea.pr.merge"],
+    "audit_label": "prgs-author-deleter",
+}
+
+CONFIG = {
+    "version": 2,
+    "contexts": {
+        "ctx": {
+            "enabled": True,
+            "gitea": {"enabled": True, "base_url": "https://gitea.example.com"},
+        }
+    },
+    "profiles": {
+        "author-no-delete": {
+            "enabled": True,
+            "context": "ctx",
+            "role": "author",
+            "username": "author-user",
+            "auth": {"type": "env", "name": "GITEA_TOKEN_AUTHOR"},
+            "allowed_operations": AUTHOR_NO_DELETE["allowed_operations"],
+            "forbidden_operations": [],
+            "execution_profile": "author-no-delete",
+        },
+        "author-with-delete": {
+            "enabled": True,
+            "context": "ctx",
+            "role": "author",
+            "username": "deleter-user",
+            "auth": {"type": "env", "name": "GITEA_TOKEN_AUTHOR"},
+            "allowed_operations": AUTHOR_WITH_DELETE["allowed_operations"],
+            "forbidden_operations": [],
+            "execution_profile": "author-with-delete",
+        },
+        "reviewer-profile": {
+            "enabled": True,
+            "context": "ctx",
+            "role": "reviewer",
+            "username": "reviewer-user",
+            "auth": {"type": "env", "name": "GITEA_TOKEN_REVIEWER"},
+            "allowed_operations": [
+                "gitea.read", "gitea.pr.review", "gitea.pr.merge",
+            ],
+            "forbidden_operations": [
+                "gitea.branch.delete", "gitea.branch.push", "gitea.pr.create",
+            ],
+            "execution_profile": "reviewer-profile",
+        },
+    },
+    "rules": {"allow_runtime_switching": False},
+}
+
+
+class TestDeleteBranchToolGate(unittest.TestCase):
+
+    def setUp(self):
+        self._preflight_snapshot = (
+            mcp_server._preflight_whoami_called,
+            mcp_server._preflight_capability_called,
+        )
+        mcp_server._preflight_whoami_called = False
+        mcp_server._preflight_capability_called = False
+        self._remotes = patch.dict(mcp_server.REMOTES, {
+            "prgs": {"host": "gitea.example.com", "org": "Example-Org",
+                     "repo": "Example-Repo"},
+        })
+        self._remotes.start()
+        mcp_server._IDENTITY_CACHE.clear()
+        patch("gitea_config.load_config", return_value={}).start()
+        patch(
+            "gitea_config.is_runtime_switching_enabled", return_value=False
+        ).start()
+        patch("gitea_audit.audit_enabled", return_value=False).start()
+        self.mock_api = patch("mcp_server.api_request").start()
+        self.mock_auth = patch(
+            "mcp_server.get_auth_header", return_value=FAKE_AUTH
+        ).start()
+
+    def tearDown(self):
+        patch.stopall()
+        mcp_server._IDENTITY_CACHE.clear()
+        mcp_server._preflight_whoami_called, mcp_server._preflight_capability_called = (
+            self._preflight_snapshot
+        )
+
+    def _set_profile(self, profile):
+        patch("mcp_server.get_profile", return_value=profile).start()
+
+    def test_blocked_without_delete_capability(self):
+        self._set_profile(AUTHOR_NO_DELETE)
+        res = gitea_delete_branch(branch="feat/branch", remote="prgs")
+        self.assertFalse(res["success"])
+        self.assertFalse(res["performed"])
+        self.assertEqual(res["required_permission"], "gitea.branch.delete")
+        self.assertTrue(res["reasons"])
+        self.assertEqual(
+            res["permission_report"]["missing_permission"],
+            "gitea.branch.delete",
+        )
+        self.mock_api.assert_not_called()
+        self.mock_auth.assert_not_called()
+
+    def test_allowed_delete_proceeds(self):
+        self._set_profile(AUTHOR_WITH_DELETE)
+        mcp_server.record_preflight_check("whoami")
+        mcp_server.record_preflight_check("capability", resolved_role="author")
+        res = gitea_delete_branch(branch="feat/branch", remote="prgs")
+        self.assertTrue(res["success"])
+        self.assertIn("deleted", res["message"])
+        delete_calls = [
+            c for c in self.mock_api.call_args_list if c.args[0] == "DELETE"
+        ]
+        self.assertTrue(delete_calls)
+
+    def test_allowed_delete_audited_with_capability_proof(self):
+        self._set_profile(AUTHOR_WITH_DELETE)
+        patch("gitea_audit.audit_enabled", return_value=True).start()
+        mock_write = patch("gitea_audit.write_event").start()
+        mcp_server.record_preflight_check("whoami")
+        mcp_server.record_preflight_check("capability", resolved_role="author")
+        self.mock_api.return_value = {}
+        gitea_delete_branch(branch="feat/branch", remote="prgs")
+        mock_write.assert_called()
+        event = mock_write.call_args[0][0]
+        self.assertEqual(event["action"], "delete_branch")
+        self.assertEqual(
+            event["request_metadata"]["required_permission"],
+            "gitea.branch.delete",
+        )
+
+
+class TestDeleteBranchResolverParity(unittest.TestCase):
+    def setUp(self):
+        self._remotes = patch.dict(mcp_server.REMOTES, {
+            "prgs": {"host": "gitea.example.com", "org": "Example-Org",
+                     "repo": "Example-Repo"},
+        })
+        self._remotes.start()
+        mcp_server._IDENTITY_CACHE.clear()
+        self._dir = tempfile.TemporaryDirectory()
+        self.config_path = os.path.join(self._dir.name, "profiles.json")
+        with open(self.config_path, "w", encoding="utf-8") as fh:
+            fh.write(json.dumps(CONFIG))
+        patch(
+            "gitea_config.is_runtime_switching_enabled", return_value=False
+        ).start()
+        patch("gitea_audit.audit_enabled", return_value=False).start()
+        self.mock_api = patch("mcp_server.api_request").start()
+        patch("mcp_server.get_auth_header", return_value=FAKE_AUTH).start()
+
+    def tearDown(self):
+        patch.stopall()
+        mcp_server._IDENTITY_CACHE.clear()
+        self._dir.cleanup()
+
+    def _env(self, profile: str) -> dict:
+        return {
+            "GITEA_MCP_CONFIG": self.config_path,
+            "GITEA_MCP_PROFILE": profile,
+            "GITEA_TOKEN_AUTHOR": "author-pass",
+            "GITEA_TOKEN_REVIEWER": "reviewer-pass",
+        }
+
+    def test_reviewer_resolver_denial_blocks_raw_tool(self):
+        with patch.dict(os.environ, self._env("reviewer-profile"), clear=True):
+            resolve = mcp_server.gitea_resolve_task_capability(
+                task="delete_branch", remote="prgs")
+            self.assertFalse(resolve["allowed_in_current_session"])
+            res = gitea_delete_branch(branch="feat/branch", remote="prgs")
+        self.assertFalse(res["success"])
+        self.assertEqual(
+            res["permission_report"]["missing_permission"],
+            resolve["required_operation_permission"],
+        )
+        delete_calls = [
+            c for c in self.mock_api.call_args_list if c.args[0] == "DELETE"
+        ]
+        self.assertFalse(delete_calls)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_llm_workflow_split.py

@@ -207,6 +207,12 @@ def test_validation_integrity_verifier_exported():
     assert callable(assess_validation_integrity_report)
 
 
+def test_validation_failure_history_verifier_exported():
+    from review_proofs import assess_validation_failure_history_report
+
+    assert callable(assess_validation_failure_history_report)
+
+
 def test_prior_blocker_skip_verifier_exported():
     from review_proofs import assess_prior_blocker_skip_proof
 

tests/test_mcp_server.py

@@ -1005,9 +1005,19 @@ class TestReviewPR(unittest.TestCase):
 # ---------------------------------------------------------------------------
 class TestDeleteBranch(unittest.TestCase):
 
+    DELETE_PROFILE = {
+        "profile_name": "test-deleter",
+        "allowed_operations": ["gitea.read", "gitea.branch.delete"],
+        "forbidden_operations": [],
+        "audit_label": "test-deleter",
+    }
+
+    @patch("mcp_server.get_profile", return_value=DELETE_PROFILE)
     @patch("mcp_server.api_request")
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
-    def test_delete_branch(self, _auth, mock_api):
+    def test_delete_branch(self, _auth, mock_api, _profile):
+        mcp_server.record_preflight_check("whoami")
+        mcp_server.record_preflight_check("capability", resolved_role="author")
         mock_api.return_value = {}
         result = gitea_delete_branch(branch="feat/branch")
         self.assertTrue(result["success"])

tests/test_reviewer_validation_failure_history.py

@@ -0,0 +1,147 @@
+"""Tests for transient validation failure history verifier (#396)."""
+import sys
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from final_report_validator import assess_final_report_validator  # noqa: E402
+from reviewer_validation_failure_history import (  # noqa: E402
+    assess_validation_failure_history_report,
+)
+
+
+def _full_history_report() -> str:
+    return "\n".join([
+        "Validation failure history",
+        "Failure #1:",
+        "Command: venv/bin/python -m pytest tests/test_worktrees.py -q",
+        "Failing test: tests/test_worktrees.py::TestWorktreeStart::test_rejects_untraceable_branches",
+        "Suspected cause: stale /tmp/gitea_issue_lock.json from prior session",
+        "Reproduced: no",
+        "On baseline master: no",
+        "PR-caused: no",
+        "What changed between runs: removed /tmp/gitea_issue_lock.json",
+        "Environmental cleanup: lock file removed before rerun",
+        "Validation: passed after transient failure investigation",
+        "Final validation command: venv/bin/python -m pytest tests/ -q",
+        "Final result: 1497 passed, 6 skipped",
+    ])
+
+
+class TestValidationFailureHistory(unittest.TestCase):
+    def test_no_failures_observed_passes(self):
+        result = assess_validation_failure_history_report(
+            "Validation: passed",
+            validation_session={"observed_failures": []},
+        )
+        self.assertTrue(result["proven"])
+
+    def test_omitted_failure_blocks(self):
+        result = assess_validation_failure_history_report(
+            "Validation: passed\n1497 passed, 6 skipped",
+            validation_session={
+                "observed_failures": [{
+                    "command": "pytest tests/test_worktrees.py -q",
+                    "failing_test": (
+                        "tests/test_worktrees.py::TestWorktreeStart::"
+                        "test_rejects_untraceable_branches"
+                    ),
+                }],
+                "final_validation_status": "passed",
+            },
+        )
+        self.assertFalse(result["proven"])
+        self.assertTrue(result["block"])
+
+    def test_full_history_with_transient_investigation_passes(self):
+        result = assess_validation_failure_history_report(
+            _full_history_report(),
+            validation_session={
+                "observed_failures": [{
+                    "command": (
+                        "venv/bin/python -m pytest tests/test_worktrees.py -q"
+                    ),
+                    "failing_test": (
+                        "tests/test_worktrees.py::TestWorktreeStart::"
+                        "test_rejects_untraceable_branches"
+                    ),
+                    "suspected_cause": "stale /tmp/gitea_issue_lock.json",
+                    "reproduced": "no",
+                    "on_baseline_master": "no",
+                    "pr_caused": "no",
+                }],
+                "final_validation_status": "passed_after_transient_failure_investigation",
+                "environmental_contamination": True,
+            },
+        )
+        self.assertTrue(result["proven"], result["reasons"])
+
+    def test_baseline_equivalent_failure_documented(self):
+        report = "\n".join([
+            "Validation failure history",
+            "Command: pytest tests/test_example.py -q",
+            "Failing test: tests/test_example.py::test_flaky",
+            "Suspected cause: pre-existing master failure",
+            "On baseline master: yes",
+            "PR-caused: no",
+            "What changed between runs: none; failure matches baseline",
+            "Validation: passed after transient failure investigation",
+        ])
+        result = assess_validation_failure_history_report(
+            report,
+            validation_session={
+                "observed_failures": [{
+                    "command": "pytest tests/test_example.py -q",
+                    "failing_test": "tests/test_example.py::test_flaky",
+                    "on_baseline_master": "yes",
+                    "pr_caused": "no",
+                }],
+                "final_validation_status": "passed_after_transient_failure_investigation",
+            },
+        )
+        self.assertTrue(result["proven"], result["reasons"])
+
+    def test_unknown_cause_plain_pass_blocks(self):
+        result = assess_validation_failure_history_report(
+            "Validation: passed",
+            validation_session={
+                "observed_failures": [{
+                    "command": "pytest tests/ -q",
+                    "failing_test": "tests/test_foo.py::test_bar",
+                    "suspected_cause": "unknown",
+                }],
+                "final_validation_status": "passed",
+                "cause_unknown": True,
+            },
+        )
+        self.assertFalse(result["proven"])
+        self.assertTrue(any("transient" in r.lower() for r in result["reasons"]))
+
+    def test_final_report_validator_rejects_omitted_failure(self):
+        result = assess_final_report_validator(
+            "Validation: passed",
+            "review_pr",
+            validation_session={
+                "observed_failures": [{
+                    "command": "pytest tests/ -q",
+                    "failing_test": "tests/test_foo.py::test_bar",
+                }],
+            },
+        )
+        self.assertTrue(result["blocked"] or result["downgraded"])
+        self.assertTrue(
+            any(
+                f.get("rule_id") == "reviewer.validation_failure_history"
+                for f in result.get("findings") or []
+            )
+        )
+
+    def test_exported_from_review_proofs(self):
+        from review_proofs import assess_validation_failure_history_report as exported
+
+        self.assertTrue(callable(exported))
+
+
+if __name__ == "__main__":
+    unittest.main()