Fix worker status tracking: use fresh DB session for notifications, commit before notifying

Agent-Logs-Url: https://github.com/christianlouis/InboxConverge/sessions/70a69601-e0b9-4a00-bcf4-0a85d2bdf6cb

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 <!-- version list -->
 
+## [Unreleased]
+
+### Fixed
+
+- Worker tasks: use a fresh DB session for `send_user_notification` calls and move notifications after `db.commit()` to prevent the post-rollback `greenlet_spawn` SQLAlchemy error.
+- Worker tasks: ensure `last_check_at` and error status are always committed before notifications, fixing accounts being endlessly re-queued after IMAP auth failures.
+
 ## v0.3.2 (2026-03-28)
 
 ### Bug Fixes

backend/app/workers/tasks.py

@@ -285,8 +285,9 @@ async def process_mail_account(account_id: int):
                             "User must re-authorise."
                         )
                         try:
+                            async with async_session_maker() as notif_db:
                                 await send_user_notification(
-                                db=db,
+                                    db=notif_db,
                                     user_id=int(account.user_id),
                                     title="InboxRescue: Gmail Authorization Expired",
                                     body=f"Your Gmail credentials for account '{account.name}' have been revoked. Please re-authorize Gmail access in Settings.",
@@ -364,9 +365,17 @@ async def process_mail_account(account_id: int):
                 account.status = AccountStatus.ERROR  # type: ignore[assignment]
                 account.last_error_at = datetime.now(timezone.utc)  # type: ignore[assignment]
                 account.last_error_message = f"{emails_failed} emails failed to forward"  # type: ignore[assignment]
+
+            await db.commit()
+
+            # Send failure notification after the commit so the status is
+            # persisted even if the notification fails.  Use a fresh session
+            # to avoid interfering with the (now-committed) main transaction.
+            if emails_failed > 0:
                 try:
+                    async with async_session_maker() as notif_db:
                         await send_user_notification(
-                        db=db,
+                            db=notif_db,
                             user_id=int(account.user_id),
                             title="InboxRescue: Mail Forwarding Failures",
                             body=f"Mail account '{account.name}': {emails_failed} email(s) failed to forward.",
@@ -375,8 +384,6 @@ async def process_mail_account(account_id: int):
                 except Exception as notify_exc:
                     logger.warning(f"Failed to send notification: {notify_exc}")
 
-            await db.commit()
-
             # Record Prometheus metrics for this completed run
             _run_status = "completed" if emails_failed == 0 else "partial_failure"
             MAIL_PROCESSING_RUNS_TOTAL.labels(status=_run_status).inc()
@@ -437,20 +444,6 @@ async def process_mail_account(account_id: int):
                     # throttles re-dispatch instead of queuing a new task every cycle.
                     account.last_check_at = datetime.now(timezone.utc)  # type: ignore[assignment]
 
-                    # Notify user about the error
-                    try:
-                        await send_user_notification(
-                            db=db,
-                            user_id=int(account.user_id),
-                            title="InboxRescue: Mail Processing Error",
-                            body=f"Error processing mail account '{account.name}': {e}",
-                            notify_on_error=True,
-                        )
-                    except Exception as notify_exc:
-                        logger.warning(
-                            f"Failed to send error notification: {notify_exc}"
-                        )
-
                 try:
                     await db.commit()
                 except Exception as commit_exc:
@@ -459,6 +452,24 @@ async def process_mail_account(account_id: int):
                         f"{account_id}: {commit_exc}"
                     )
 
+            # Send error notification after the commit (and outside the run/account
+            # guards) so the status is always persisted first.  Use a fresh session
+            # to avoid the post-rollback session's broken greenlet context causing
+            # the notification query itself to fail with "greenlet_spawn has not
+            # been called".
+            if "account" in locals() and account is not None:
+                try:
+                    async with async_session_maker() as notif_db:
+                        await send_user_notification(
+                            db=notif_db,
+                            user_id=int(account.user_id),
+                            title="InboxRescue: Mail Processing Error",
+                            body=f"Error processing mail account '{account.name}': {e}",
+                            notify_on_error=True,
+                        )
+                except Exception as notify_exc:
+                    logger.warning(f"Failed to send error notification: {notify_exc}")
+
 
 @celery_app.task(base=AsyncTask, name="app.workers.tasks.process_all_enabled_accounts")
 async def process_all_enabled_accounts():

docs/TODO.md

@@ -4,6 +4,7 @@ Comprehensive task breakdown for repository improvements and production readines
 
 ## ✅ Recently Completed
 
+- [x] Fixed worker `send_user_notification` using rolled-back DB session causing `greenlet_spawn has not been called` errors; status/`last_check_at` now always committed before sending notifications via a fresh session.
 - [x] **Pull Now**: Added "Pull Now" button on Accounts page that immediately queues a `process_mail_account` Celery task via `POST /mail-accounts/{id}/pull-now`. Button shows spinner while in flight and is disabled for inactive accounts.
 - [x] Fixed 21 mypy type errors: `Column[T]` vs native type mismatches in `notification_service.py`, `mail_processor.py`, `auth.py`, `tasks.py`, `providers.py`, `mail_accounts.py`, and `main.py` (`lifespan` parameter rename).
 - [x] **Provider logos rework**: Logos now displayed as full-width banner strips at the top of each account card using `next/image fill + object-contain`. Handles all aspect ratios (1:1 square to 6:1 wordmark) without distortion. Proton Mail added.