Problemsby GlyphTrouble with Prefect flow
14 posts from 11 people12d activeFading, +0 this week
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Flow run stays Running forever when setup_run_context raises
### Bug summary If `setup_run_context()` raises, e.g. because the result storage block doesn't exist, the flow run is left `Running` forever. `initialize_run`'s `except Exception: raise` sets no state. It should crash the run, as the `BaseException` branch does. ### Version info...
Task run recorder drops valid events when one event in a batch references a missing flow run
...batch fails. The failed events are retried together with new ones, so the bad event keeps failing later batches until valid events from other flow runs run out of retries and are dropped. As a result, task runs of healthy flow runs can be left without their final state, or never...
`POST /flow_runs/{id}/resume` returns 500 when `run_input` contains an integer outside the 64-bit range
### Bug summary Resuming a paused flow run returns 500 when `run_input` contains an integer outside the 64-bit range. The run stays `PAUSED` and no input is stored. #23429 fixes the same error in the flow run list endpoints, but doesn't change this one. Output: Server error:...
Flow run graph polls graph-v2 every second for the whole run, rebuilding the full graph each time
### Bug summary The flow run graph in the UI re-fetches `GET /flow_runs/{id}/graph-v2` every ~1 second for as long as the flow run is running. Each request rebuilds the full graph on the server. With a few browser tabs left open on long-running flow runs, this polling became the...
Flow rescheduled after SIGTERM skips previously triggered pause_flow_run calls
### Bug summary ### Description We encountered an issue where a Prefect flow using `pause_flow_run()` for mandatory human validations was rescheduled following a Kubernetes pod termination. On the new execution attempt, the flow restarted from the beginning but skipped both...
prefect flow-run execute exits 0 when the flow run crashes and the Crashed report fails, leaving the run Running forever
### Bug summary # `prefect flow-run execute` exits 0 when the flow run crashes and the `Crashed` report fails, leaving the run `Running` forever > Debugged and reproduced by Claude (Anthropic's Claude Code), from a production incident on our self-hosted > Prefect server. Repro...
JSON flow result with a "data" or "result" key reads back wrong from the API
### Bug summary A flow with `result_serializer="json"` and persisted results that returns a dict containing a `data` or `result` key gets the wrong value back when the result is loaded from storage. `{"data": [1, 2, 3], "total": 3}` comes back as `[1, 2, 3]`, `{"result": 5,...
Breaking out of an async generator flow marks the run Failed after Completed
### Bug summary When I stop consuming an async generator flow early (`break` and then `aclose()`), the flow run is first set to `Completed` and then to `Failed` with `AttributeError: 'async_generator' object has no attribute 'throw'`. Both the `on_completion` and the...
UI v2: a flow run's artifacts can't be opened directly from the Artifacts tab or the run graph
### Bug summary In the V2 UI, the artifacts a flow run produced can no longer be opened directly from the flow run page. In the V1 UI, both of these went straight to the artifact. 1. **Artifacts tab:** clicking an artifact card with a key opens `/artifacts/key/ `, which lists...
[UI] Open flow run on click in flow runs timeline
### Describe the current behavior Currently, it is possible to open a flow run by clicking on its name in the list of flow runs, below the flow runs plot. However, clicking on a flow run in the plot itself does nothing. ### Describe the proposed behavior It would be great to...
Flow ends COMPLETED when it returns a list of .map() results containing a FAILED task (states nested one level are ignored)
### Bug summary A flow that returns a list containing the results of two or more `.map()` calls ends `COMPLETED` even when one of the mapped tasks `FAILED`. The same flow returning a flat list of the same futures ends `FAILED('1/2 states failed.')`. ### Cause...
Add Quick Run and Custom Run to the flow's Deployments tab
### Current behavior In V2, the row menu on a flow's **Deployments** tab offers only **Copy ID**. Users must open a deployment's detail page to reach its Run menu, even though the global Deployments table already provides Quick Run and Custom Run actions. Adding those actions to...
V2 UI feedback: Difficult to move the cursor into the Flow Run tooltip
...the tooltip to show information for that neighboring run. As a result, it is very difficult to move the cursor into the tooltip and interact with its links. Expected behavior: The tooltip should remain open for the originally hovered flow run while the cursor moves toward or...
Dashboard deployment quick run flow run page renders in the Scheduled state and never updates
...the stuck tab also immediately shows the correct state, so this appears to be the page failing to poll / re-render rather than a server-side state problem. ### Reproduction 1. Open a deployment in the UI 2. Click "Quick run" 3. Click "View run" in the toast that appears 4....
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About this problem
Evidence
14 posts from 11 people in 1 place, about 1 a week over 64 days. Mostly on PrefectHQ/prefect. Tools named alongside: Kubernetes, PostgreSQL, GitHub, Claude Code.
Frustration Frustration 0 of 3· Seen on GitHub issues
How it was grouped
Posts about Prefect with no known issue, sharing the word "flow". First post Aug 28, 2026, latest Oct 30, 2026. Corroborated: 3 or more posts from 2 or more people or places. Method
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