Log errors on retry attempts too

Same fix as the Perpetual error logging — Retry.handle_failure() was
returning True and swallowing the exception. Now each retry attempt
logs the error at ERROR level with the full traceback before the
reschedule info line.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: chrisguidry

src/docket/dependencies/_retry.py

@@ -89,6 +89,15 @@ async def handle_failure(self, execution: Execution, outcome: TaskOutcome) -> bo
 
         worker = current_worker.get()
         TASKS_RETRIED.add(1, {**worker.labels(), **execution.general_labels()})
+
+        if outcome.exception:
+            logger.error(
+                "↩ [%s] %s",
+                format_duration(outcome.duration.total_seconds()),
+                execution.call_repr(),
+                exc_info=outcome.exception,
+            )
+
         logger.info(
             "↫ [%s] %s",
             format_duration(outcome.duration.total_seconds()),

tests/fundamentals/test_retries.py

@@ -1,5 +1,6 @@
 """Tests for error handling and retry strategies."""
 
+import logging
 from datetime import datetime, timedelta
 from typing import Callable
 from unittest.mock import AsyncMock
@@ -28,6 +29,31 @@ async def test_errors_are_logged(
     assert "Faily McFailerson" in caplog.text
 
 
+async def test_retry_errors_are_logged(
+    docket: Docket, worker: Worker, caplog: pytest.LogCaptureFixture
+):
+    """Each retry attempt logs the exception at ERROR level."""
+    calls = 0
+
+    async def the_task(retry: Retry = Retry(attempts=3)):
+        nonlocal calls
+        calls += 1
+        raise ValueError("attempt failed")
+
+    await docket.add(the_task)()
+
+    with caplog.at_level(logging.ERROR):
+        await worker.run_until_finished()
+
+    assert calls == 3
+    error_records = [r for r in caplog.records if r.levelno == logging.ERROR]
+    assert any(
+        "attempt failed" in r.getMessage()
+        or (r.exc_info and "attempt failed" in str(r.exc_info[1]))
+        for r in error_records
+    )
+
+
 async def test_supports_simple_linear_retries(
     docket: Docket, worker: Worker, now: Callable[[], datetime]
 ):