Sample
six 1.17.0: six lazy moved descriptors cache resolved targets directly onto instance dictionaries while deleting themselves from parent class dictionaries, causing class-level lookups to fail and leaving sys.meta_path importers decoupled from remove_move and add_move
Verified sample for pypi six 1.17.0: six lazy moved descriptors cache resolved targets directly onto instance dictionaries while deleting themselves from…
sha256:b632b8e946a5c728dc7d1654280ec14c45ffffd3c37cf0d43ddaa4ece84a11da
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 |
2026-08-17 |
| 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
- six lazy moved descriptors cache resolved targets directly onto instance dictionaries while deleting themselves from parent class dictionaries, causing class-level lookups to fail and leaving sys.meta_path importers decoupled from remove_move and add_move
- Packages
- Symbols
-
- six._LazyDescr
- six._MovedItems
- six._SixMetaPathImporter
- six.add_move
- six.remove_move
- six.MovedModule
- six.MovedAttribute
- six.reraise
- Environment
- python
- Created
- 2026-08-17T07:05:16Z
Contract
- Accessing an attribute on six.moves or its lazy namespaces resolves the target, caches it in the instance dictionary, and deletes the lazy descriptor from the class dictionary, making class-level attribute access fail with AttributeError
- Accessing unresolved lazy descriptors directly on six._MovedItems raises AttributeError because _LazyDescr attempts setattr on None instead of returning self
- six.remove_move purges moves from _MovedItems and six.moves instance dictionaries while leaving six._importer.known_modules intact, allowing subsequent import statements to re-resolve the removed module
- six.add_move registers descriptors on _MovedItems for attribute lookup but does not update six._importer.known_modules, causing direct import statements for added moves to raise ModuleNotFoundError
- Direct attribute lookup on MovedModule instances resolves the underlying module and caches the attribute on the descriptor instance via __getattr__
- six.reraise clears its local value and traceback references in a finally block to prevent circular reference cycles between execution frames and traceback objects
Files
- NOTES.md
- csx.json
- requirements.txt
- test/__init__.py
- test/contract.py