fix: classify distinct check failures correctly

strix/fix/prepare.py

@@ -430,6 +430,14 @@ def _verification_gaps(
     return list(dict.fromkeys(gaps))
 
 
+def _matches_baseline_failure(result: CheckResult) -> bool:
+    if result.baseline_status is not CheckStatus.FAILED:
+        return False
+    candidate_output = " ".join(result.output.split())
+    baseline_output = " ".join((result.baseline_output or "").split())
+    return bool(candidate_output and candidate_output == baseline_output)
+
+
 async def prepare_fix(  # noqa: PLR0915
     request: FixPreparationRequestV1,
     workspace: Path,
@@ -593,9 +601,7 @@ async def prepare_fix(  # noqa: PLR0915
                 )
 
             failed = [result for result in required if result.status is CheckStatus.FAILED]
-            baseline_failures = [
-                result for result in failed if result.baseline_status is CheckStatus.FAILED
-            ]
+            baseline_failures = [result for result in failed if _matches_baseline_failure(result)]
             if baseline_failures:
                 blocker = PreparationBlocker(
                     kind=BlockerKind.REPOSITORY_BASELINE,

tests/test_fix_preparation.py

@@ -420,6 +420,48 @@ async def test_repository_baseline_failure_is_a_typed_blocker(
     assert result.attempts == 1
 
 
+@pytest.mark.asyncio
+async def test_different_candidate_and_baseline_failures_are_repairable(
+    tmp_path: Path,
+) -> None:
+    workspace, commit = _workspace(tmp_path)
+    repairs = 0
+
+    async def repair(
+        _context: PreparationContext,
+        _feedback: list[CheckResult],
+    ) -> RepairOutcome:
+        nonlocal repairs
+        repairs += 1
+        return await _noop_repair(_context, _feedback)
+
+    async def runner(_workspace: Path, command: CommandSpec) -> CheckResult:
+        return CheckResult(
+            name=command.name,
+            argv=command.argv,
+            status=CheckStatus.FAILED,
+            exit_code=1,
+            duration_seconds=0,
+            output="candidate-specific failure",
+            required=command.required,
+            baseline_status=CheckStatus.FAILED,
+            baseline_output="different pre-existing failure",
+        )
+
+    result = await prepare_fix(
+        _request(_candidate(commit)),
+        workspace,
+        repair=repair,
+        verify=_verified,
+        command_runner=runner,
+    )
+
+    assert result.state is PreparationState.FAILED
+    assert result.blocker is None
+    assert result.attempts == 2
+    assert repairs == 2
+
+
 @pytest.mark.asyncio
 async def test_unavailable_required_check_is_a_typed_blocker(tmp_path: Path) -> None:
     workspace, commit = _workspace(tmp_path)