uv exits with code `-1073741819` and no error message on Windows

[monchin]

Summary

My uv recently broke, and I don't know why. Below are some logs

 uv tool install isort -vv
DEBUG uv 0.7.9 (13a86a23b 2025-05-30)
DEBUG Searching for default Python interpreter in managed installations, search path, or registry
DEBUG Searching for managed installations at `C:\Users\mench\AppData\Roaming\uv\python`
DEBUG Found managed installation `cpython-3.12.10-windows-x86_64-none`
TRACE Cached interpreter info for Python 3.12.10, skipping probing: C:\Users\mench\AppData\Roaming\uv\python\cpython-3.12.10-windows-x86_64-none\python.exe
DEBUG Found `cpython-3.12.10-windows-x86_64-none` at `C:\Users\mench\AppData\Roaming\uv\python\cpython-3.12.10-windows-x86_64-none\python.exe` (managed installations)
TRACE Checking lock for `C:\Users\mench\AppData\Roaming\uv\tools` at `C:\Users\mench\AppData\Roaming\uv\tools\.lock`
DEBUG Acquired lock for `C:\Users\mench\AppData\Roaming\uv\tools`
DEBUG Checking for Python environment at `C:\Users\mench\AppData\Roaming\uv\tools\isort`
DEBUG Using request timeout of 30s
DEBUG Solving with installed Python version: 3.12.10
DEBUG Solving with target Python version: >=3.12.10
TRACE Assigned packages:
TRACE Chose package for decision: root. remaining choices:
DEBUG Adding direct dependency: isort*
TRACE Assigned packages: root==0a0.dev0
TRACE Chose package for decision: isort. remaining choices:
TRACE Fetching metadata for isort from https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/isort/
TRACE Checking lock for `C:\Users\mench\AppData\Local\uv\cache\simple-v16\index\e367fd55faf540ee\isort.lock` at `C:\Users\mench\AppData\Local\uv\cache\simple-v16\index\e367fd55faf540ee\isort.lock`
DEBUG Acquired lock for `C:\Users\mench\AppData\Local\uv\cache\simple-v16\index\e367fd55faf540ee\isort.lock`
TRACE No cache entry exists for C:\Users\mench\AppData\Local\uv\cache\simple-v16\index\e367fd55faf540ee\isort.rkyv
DEBUG No cache entry for: https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/isort/
TRACE Sending fresh GET request for https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/isort/
TRACE Handling request for https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/isort/ with authentication policy auto
TRACE Request for https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/isort/ is unauthenticated, checking cache
TRACE No credentials in cache for URL https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/isort/
TRACE Attempting unauthenticated request for https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/isort/

uv add numpy -vv
DEBUG uv 0.7.9 (13a86a23b 2025-05-30)
DEBUG Found project root: `C:\Users\mench\Work\Private\tests\abb`
DEBUG No workspace root found, using project root
TRACE Checking lock for `C:\Users\mench\Work\Private\tests\abb` at `C:\Users\mench\AppData\Local\Temp\uv-37f0429431815cfc.lock`
DEBUG Acquired lock for `C:\Users\mench\Work\Private\tests\abb`
DEBUG Reading Python requests from version file at `C:\Users\mench\Work\Private\tests\abb\.python-version`
DEBUG Using Python request `3.12` from version file at `.python-version`
DEBUG Checking for Python environment at `.venv`
DEBUG Searching for Python 3.12 in managed installations, search path, or registry
DEBUG Searching for managed installations at `C:\Users\mench\AppData\Roaming\uv\python`
DEBUG Found managed installation `cpython-3.12.10-windows-x86_64-none`
TRACE Cached interpreter info for Python 3.12.10, skipping probing: C:\Users\mench\AppData\Roaming\uv\python\cpython-3.12.10-windows-x86_64-none\python.exe
DEBUG Found `cpython-3.12.10-windows-x86_64-none` at `C:\Users\mench\AppData\Roaming\uv\python\cpython-3.12.10-windows-x86_64-none\python.exe` (managed installations)
Using CPython 3.12.10
Creating virtual environment at: .venv
DEBUG Using base executable for virtual environment: C:\Users\mench\AppData\Roaming\uv\python\cpython-3.12.10-windows-x86_64-none\python.exe
DEBUG Released lock at `C:\Users\mench\AppData\Local\Temp\uv-37f0429431815cfc.lock`
DEBUG Using request timeout of 30s
DEBUG Found static `pyproject.toml` for: abb @ file:///C:/Users/mench/Work/Private/tests/abb
DEBUG No workspace root found, using project root
TRACE Performing lookahead for abb @ file:///C:/Users/mench/Work/Private/tests/abb
DEBUG Solving with installed Python version: 3.12.10
DEBUG Solving with target Python version: >=3.12
TRACE Assigned packages:
TRACE Chose package for decision: root. remaining choices:
DEBUG Adding direct dependency: abb*
TRACE Assigned packages: root==0a0.dev0
TRACE Chose package for decision: abb. remaining choices:
DEBUG Searching for a compatible version of abb @ file:///C:/Users/mench/Work/Private/tests/abb (*)
DEBUG Adding direct dependency: numpy*
TRACE Assigned packages: root==0a0.dev0, abb==0.1.0
TRACE Chose package for decision: numpy. remaining choices:
TRACE Fetching metadata for numpy from https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/numpy/
TRACE Checking lock for `C:\Users\mench\AppData\Local\uv\cache\simple-v16\index\e367fd55faf540ee\numpy.lock` at `C:\Users\mench\AppData\Local\uv\cache\simple-v16\index\e367fd55faf540ee\numpy.lock`
DEBUG Acquired lock for `C:\Users\mench\AppData\Local\uv\cache\simple-v16\index\e367fd55faf540ee\numpy.lock`
TRACE No cache entry exists for C:\Users\mench\AppData\Local\uv\cache\simple-v16\index\e367fd55faf540ee\numpy.rkyv
DEBUG No cache entry for: https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/numpy/
TRACE Sending fresh GET request for https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/numpy/
TRACE Handling request for https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/numpy/ with authentication policy auto
TRACE Request for https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/numpy/ is unauthenticated, checking cache
TRACE No credentials in cache for URL https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/numpy/
TRACE Attempting unauthenticated request for https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple/numpy/

My ~/.config/uv/uv.toml:

[[index]]
url = "https://mirrors.tuna.tsinghua.edu.cn/pypi/web/simple"
default = true

It worked in the past, but I don't know why it doesn't work recently.

Platform

win11

Version

uv 0.7.9 (13a86a2 2025-05-30)

Python version

3.12.10

[zanieb]

Sorry but what's the error?

[monchin]

Sorry but what's the error?

Both tool install and add failed with no further information

[zanieb]

That's confusing. What's the exit code? e.g., $LASTEXITCODE

[monchin]

That's confusing. What's the exit code? e.g., $LASTEXITCODE

-1073741819

I looked up in the calculator and it's C000 0005 in HEX

[zanieb]

Interesting, this is the same as #13812

It's unclear what's happening in this situation. We suspect something on Windows is killing uv.

[zanieb]

Does it resolve if you set UV_STACK_SIZE= 1048576?

[monchin]

Does it resolve if you set UV_STACK_SIZE= 1048576?

I set it as an env var, and it doesn't work