Pydantic warning: PydanticSerializationUnexpectedValue
Metadata
Current evaluation
PydanticSerializationUnexpectedValue warning emitted during Project.marshal() when rockcraft.yaml checks contain an ExecCheck entry. Maintainer reproduced it locally and narrowed it to a tagged-union serialization issue in the Check/ExecCheck model; no fix committed yet.
Suggested action: keep open
Reason: Maintainer gcomneno actively reproduced the warning and diagnosed it as a tagged-union serialization problem in the Check/ExecCheck model (last activity 153 days ago), so it is triaged and valid. The code still uses a custom pydantic.Discriminator(_get_check_tag) that only accepts Mapping input, which is why serialization of an ExecCheck instance triggers the warning; no fix commit exists yet.
Impact:
35
Quick Win:
21.0
Staleness:
45
Complexity:
40
Confidence:
70
Support Request:
10
Issue body
### Check existing issues
- [x] I've verified that this bug isn't described by any existing issues.
### Bug description
Recently I'm getting this additional warning output
### Steps to reproduce
`rockcraft pack`
### Environment
concierge prepare -p k8s
### rockcraft.yaml
```yaml
---
name: gubernator
version: 3.0.0
summary: High-performance, distributed rate-limiting service
description: |
Gubernator is a high-performance, distributed rate-limiting service.
license: Apache-2.0
platforms: {amd64: null, arm64: null}
base: ubuntu@24.04
parts:
go-deps:
plugin: nil
build-packages:
- golang-go
gubernator:
plugin: go
source: https://github.com/gubernator-io/gubernator.git
source-type: git
# The tip of the v3.0 branch fails the health check
# source-branch: v3.0
# A known good revision from v3.0 branch from June 2024
source-commit: 2903b1b566dc9beab322e37ecef4aff50c1a7a97
stage-packages:
- ca-certificates
after:
- go-deps
services:
gubernator:
override: replace
startup: enabled
command: /bin/gubernator
environment:
GUBER_TRACING_LEVEL: DEBUG
GUBER_HTTP_ADDRESS: 0.0.0.0:80
GUBER_GRPC_ADDRESS: 0.0.0.0:81
on-success: shutdown
on-failure: shutdown
on-check-failure:
online: shutdown
checks:
online:
override: replace
exec:
# The healthcheck binary is provided by gubernator, it uses same env vars as the daemon
command: /bin/healthcheck
period: 3s
```
### Log output
```shell
Skipping prime for pebble (already ran)/snap/rockcraft/4238/lib/python3.12/site-packages/pydantic/main.py:464: UserWarning: Pydantic serializer warnings:
PydanticSerializationUnexpectedValue(Defaulting to left to right union serialization - failed to get discriminator value for tagged union serialization [input_value=ExecCheck(override='repla...None, working_dir=None)), input_type=ExecCheck])
return self.__pydantic_serializer__.to_python(
```
Evaluation history
| Date | Model | Scores | Action | Summary |
|---|---|---|---|---|
| qwen/qwen3.8-27b |
Impact:
35
Quick Win:
21.0
Staleness:
45
Complexity:
40
Confidence:
70
Support Request:
10
|
keep open | PydanticSerializationUnexpectedValue warning emitted during Project.marshal() when rockcraft.yaml checks contain an ExecCheck entry. Maintainer reproduced it locally and narrowed it to a tagged-union serialization issue in the Check/ExecCheck model; no fix committed yet. | |
| qwen/qwen3.6-35b-a3b |
Staleness:
55
Complexity:
45
Confidence:
85
Support Request:
5
|
needs triage | Unlabelled bug report about a Pydantic v2 serialization warning during rockcraft pack. Reproduced and isolated to Project.marshal() with ExecCheck models, but remains inactive for over 112 days without labels or maintainer assignment. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
45
Complexity:
30
Confidence:
85
Support Request:
10
|
keep open | Reports a Pydantic serialization warning during rockcraft pack when marshaling ExecCheck objects. A maintainer reproduced it and identified it as a tagged-union serialization warning, but no fix has been implemented yet. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
65
Complexity:
40
Confidence:
75
Support Request:
10
|
needs triage | Pydantic serialization warning during rockcraft pack when marshalling ExecCheck objects. Reproduced and analyzed by a contributor, but remains unlabelled, unassigned, and inactive for over three months. | |
| qwen3.6-35b-a3b-mtp-q6 |
Staleness:
65
Complexity:
40
Confidence:
85
Support Request:
10
|
needs triage | Pydantic serialization warning triggers during Project marshal when handling ExecCheck objects. Output remains correct, indicating a tagged-union serialization quirk rather than a validation bug. Reproduced locally and awaiting triage. |
Update history
No update history recorded yet.
Related issues
No related issues found above the similarity threshold.