Sample
joblib 1.5.3: Handle closure serialization failures and backend fallback when switching joblib from loky to multiprocessing
Verified sample for pypi joblib 1.5.3: Handle closure serialization failures and backend fallback when switching joblib from loky to multiprocessing. The…
sha256:7786cfc40f400486765033eec7c04f3a21347d8f8513d308a4911a5ce6363569
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
python linux x64 python python pip
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| python 3.12 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · python@1 |
2026-08-15 |
| python 3.12 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · python@1 |
2026-08-18 |
Case
HOW- Goal
- Handle closure serialization failures and backend fallback when switching joblib from loky to multiprocessing
- Packages
- Symbols
-
- joblib.Parallel
- joblib.delayed
- joblib.wrap_non_picklable_objects
- joblib.parallel_backend
- joblib.parallel.DEFAULT_BACKEND
- joblib.parallel.get_active_backend
- joblib.externals.loky.backend.context.START_METHODS
- Environment
- python
- Created
- 2026-08-15T17:14:38Z
Contract
- assert jp.DEFAULT_BACKEND == 'loky' and isinstance(jp.get_active_backend()[0], jp.LokyBackend)
- assert 'loky' in loky_ctx.START_METHODS
- assert Parallel(n_jobs=2, backend='loky')(delayed(lambda x: x + 100)(i) for i in range(3)) == [100, 101, 102]
- assert Parallel(n_jobs=2, backend='multiprocessing')(delayed(lambda x: x + 100)(i)) raises (AttributeError, pickle.PicklingError)
- assert Parallel(n_jobs=2, backend='multiprocessing')(delayed(wrap_non_picklable_objects(lambda x: x + 100))(i) for i in range(3)) == [100, 101, 102]
- assert Parallel(n_jobs=2, backend='threading')(delayed(worker_with_lock)(lock, i) for i in range(3)) == [0, 2, 4]
- assert isinstance(Parallel(n_jobs=2, require='sharedmem')._backend, jp.ThreadingBackend)
- assert Parallel(backend='multiprocessing', require='sharedmem') raises ValueError
Files
- NOTES.md
- csx.json
- pyproject.toml
- requirements.lock
- requirements.txt
- test/contract.py