Fix gunicorn worker crashes on macOS#2839
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crivetimihai merged 2 commits intomainfrom Feb 11, 2026
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kevalmahajan
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Tested on mac OS, works as expected.
On macOS, gunicorn's preload feature causes SIGSEGV crashes when using uvicorn workers with async libraries (SQLAlchemy, asyncio). This is due to macOS's strict fork-safety requirements. Changes: - Disable preload_app by default on macOS in both config and shell script - Users can override with GUNICORN_PRELOAD_APP=true if needed Refs: benoitc/gunicorn#2761 Closes #2837 Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>
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crivetimihai
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* fix: disable preload on macOS to prevent worker SIGSEGV crashes On macOS, gunicorn's preload feature causes SIGSEGV crashes when using uvicorn workers with async libraries (SQLAlchemy, asyncio). This is due to macOS's strict fork-safety requirements. Changes: - Disable preload_app by default on macOS in both config and shell script - Users can override with GUNICORN_PRELOAD_APP=true if needed Refs: benoitc/gunicorn#2761 Closes #2837 Signed-off-by: Madhav Kandukuri <madhav165@gmail.com> * lint Signed-off-by: Mihai Criveti <crivetimihai@gmail.com> --------- Signed-off-by: Madhav Kandukuri <madhav165@gmail.com> Signed-off-by: Mihai Criveti <crivetimihai@gmail.com> Co-authored-by: Mihai Criveti <crivetimihai@gmail.com>
kcostell06
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* fix: disable preload on macOS to prevent worker SIGSEGV crashes On macOS, gunicorn's preload feature causes SIGSEGV crashes when using uvicorn workers with async libraries (SQLAlchemy, asyncio). This is due to macOS's strict fork-safety requirements. Changes: - Disable preload_app by default on macOS in both config and shell script - Users can override with GUNICORN_PRELOAD_APP=true if needed Refs: benoitc/gunicorn#2761 Closes IBM#2837 Signed-off-by: Madhav Kandukuri <madhav165@gmail.com> * lint Signed-off-by: Mihai Criveti <crivetimihai@gmail.com> --------- Signed-off-by: Madhav Kandukuri <madhav165@gmail.com> Signed-off-by: Mihai Criveti <crivetimihai@gmail.com> Co-authored-by: Mihai Criveti <crivetimihai@gmail.com>
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🐛 Bug-fix PR
Fixes #2837
Summary
Disables gunicorn's
--preloadoption by default on macOS to prevent worker processes from crashing with SIGSEGV errors.Problem
On macOS, running
make servecauses gunicorn workers to crash immediately after spawning:This happens because macOS has strict fork-safety requirements. When
--preloadis used, the application code (including SQLAlchemy and asyncio) is loaded in the master process before workers are forked. The forked workers inherit invalid state and crash when trying to use these libraries.Changes
gunicorn.config.py
platformmodulepreload_app = platform.system() != "Darwin"to disable preload on macOSworker_class = "uvicorn.workers.UvicornWorker"configurationrun-gunicorn.sh
uname -scheckGUNICORN_PRELOAD_APP=falseby default on macOSGUNICORN_PRELOAD_APP=truedefault on Linux and other platformsTesting
make serve- workers spawn and stay running--preloadflag is not passed on macOSPreload App: falseshown in startup logs on macOSBackwards Compatibility
GUNICORN_PRELOAD_APP=trueif they need preload on macOS🧪 Verification
make lintmake test📐 MCP Compliance (if relevant)
✅ Checklist
make black isort pre-commit)