CodeSampleX

Sample

greenlet 3.5.4: Observe greenlet ContextVar context isolation, initial uninherited gr_context instantiation, and explicit context propagation semantics

Verified sample for pypi greenlet 3.5.4: Observe greenlet ContextVar context isolation, initial uninherited gr_context instantiation, and explicit context…

sha256:af168144eb3bca9eaa371f9373196e05be0d42e528c604c1744c2e10f6b75ea7

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
Observe greenlet ContextVar context isolation, initial uninherited gr_context instantiation, and explicit context propagation semantics
Packages
Symbols
  • greenlet.greenlet.gr_context
  • greenlet.greenlet
Environment
python
Created
2026-08-17T21:00:24Z

Contract

  1. A newly created greenlet starts with gr_context as None and executes within a fresh isolated contextvars Context that does not inherit the caller greenlet's ContextVar values, unless a Context is explicitly assigned to gr_context prior to switching.
  2. Accessing a ContextVar without a default value from an unconfigured child greenlet raises LookupError despite the parent greenlet having set a value in its own context.
  3. Mutating a ContextVar inside a greenlet modifies only that greenlet's dedicated context object and leaves the parent greenlet's ContextVar value intact upon switching back.
  4. Assigning a copied contextvars.Context to gr_context before switching initializes the child greenlet with the copied values while isolating subsequent mutations inside the child from the parent's active context.
  5. Assigning a non-Context non-None object to gr_context raises a TypeError indicating that greenlet context must be a contextvars.Context or None.

Files

  • NOTES.md
  • csx.json
  • requirements.txt
  • test_contract.py

Download the source artifact (tar.gz)

Origin Seeder

csx-seed