pytest-race
Race conditions tester for pytest
Decision gist · record as of 2026-08-14
Yes, if you need to test for race conditions in a pytest suite and are willing to accept the maintenance risk. The package is simple, has no dependencies, and works for its stated purpose. However, verify compatibility with your pytest and Python versions first, since the project is no longer maintained.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.7+ and pytest 2.9.0+
- Installation is straightforward with no runtime dependencies.
- However, the project is abandoned—last updated in 2022 with no recent maintenance, so compatibility with newer versions is uncertain.
License · maintenance · safety
BSD 3-Clause License (permissive) — BSD 3-Clause License is permissive and poses no restrictions on use, modification, or distribution in proprietary or open-source projects.
last release 2022-06-07 (1529 days) · last repo commit 2022-06-07 · 6 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 792,803 downloads/mo, #5,044 on PyPI
Alternatives
Verify before relying
pip install pytest-race
from time import sleep
def test_race(start_race):
def actual_test():
global ACCUMULATOR
ACCUMULATOR += 1
assert ACCUMULATOR > 0
start_race(threads_num=2, target=actual_test)- Whether the fixture works reliably with current pytest versions (last tested in 2022)
- Whether the threading approach reliably surfaces race conditions or if timing-dependent tests may be flaky
What it is and what it does
pytest-race is a pytest plugin that adds a `start_race` fixture for testing code that may have race conditions. It runs a test function concurrently in multiple threads and checks whether the code behaves correctly under concurrent access. The fixture accepts a thread count and a test callable, then executes that callable in parallel threads to expose timing-dependent bugs.
The package has no runtime dependencies beyond pytest itself, making it lightweight to add to a test suite. However, it has been abandoned since 2022, so compatibility with modern pytest and Python versions is uncertain. The approach of using threads to surface race conditions is inherently probabilistic—bugs may not always manifest in a single test run.
Use it for
- Verify that global state or shared variables are protected against concurrent modification in multi-threaded code.
- Test thread-safe implementations of caches, counters, or other mutable objects accessed from multiple threads.
- Detect data corruption or assertion failures that occur only under concurrent access patterns.
- Validate that locks or synchronization primitives are correctly placed in critical sections.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need to test for race conditions in a pytest suite and are willing to accept the maintenance risk.
The package is simple, has no dependencies, and works for its stated purpose. However, verify compatibility with your pytest and Python versions first, since the project is no longer maintained.
Install
pytest-race on PyPI
Before you install
Installation is straightforward with no runtime dependencies. However, the project is abandoned—last updated in 2022 with no recent maintenance, so compatibility with newer versions is uncertain.
Requires Python 3.7+ and pytest 2.9.0+
License in practice
BSD 3-Clause License is permissive and poses no restrictions on use, modification, or distribution in proprietary or open-source projects.
Quickstart
pip install pytest-race
from time import sleep
def test_race(start_race):
def actual_test():
global ACCUMULATOR
ACCUMULATOR += 1
assert ACCUMULATOR > 0
start_race(threads_num=2, target=actual_test)Verify before relying
- Whether the fixture works reliably with current pytest versions (last tested in 2022)
- Whether the threading approach reliably surfaces race conditions or if timing-dependent tests may be flaky
Package facts
| License | BSD 3-Clause License permissive |
| Python support | Not specified |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | None |
| Maintenance | Abandoned 1,529 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 792,803 / month, #5,044 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 4 - BetaFramework :: PytestIntended Audience :: DevelopersLicense :: OSI Approved :: BSD LicenseOperating System :: OS IndependentProgramming Language :: PythonProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Topic :: Software Development :: Testing |
Evidence: pytest_race-0.2.0-py3-none-any.whl
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