Inconsistent behavior with conda/pip

[adusamr]

Question

I ran below commands in powershell and the import texterrors crashed only with uv:

uv venv --python 3.12
uv pip install PyQt6==6.9.1 texterrors==0.5.1
uv run python -X faulthandler -c 'import texterrors; import PyQt6; print("success")' # success
uv run python -X faulthandler -c 'import PyQt6; import texterrors; print("success")' # Windows fatal exception: access violation

conda create -n conda_test python=3.12
conda activate conda_test
pip install PyQt6==6.9.1 texterrors==0.5.1
python -X faulthandler -c 'import texterrors; import PyQt6; print("success")' # success
python -X faulthandler -c 'import PyQt6; import texterrors; print("success")' # success

there was no error also with pip only.

For this specific issue, just sticking with the import texterrors; import PyQt6 order or updating both to the newest versions resolve the issue.

I'm reporting this for showing the possible inconsistency with conda/pip.
If there is any way to avoid this kind of issue, I'd appreciate it.

Platform

Windows 11 24H2

Version

uv 0.10.2 (a788db7e5 2026-02-10)

[zanieb]

Can you share the full error?

Are you using a uv managed Python version?

[adusamr]

full error message:

PS C:\Users\pc\Documents\aaaa\uv_test> uv run python -X faulthandler -c 'import PyQt6; import texterrors; print("success")'
Windows fatal exception: access violation

Current thread 0x00000974 (most recent call first):
  File "<frozen importlib._bootstrap>", line 488 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 1293 in create_module
  File "<frozen importlib._bootstrap>", line 813 in module_from_spec
  File "<frozen importlib._bootstrap>", line 921 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1331 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1360 in _find_and_load
  File "C:\Users\pc\Documents\aaaa\uv_test\.venv\Lib\site-packages\texterrors\texterrors.py", line 12 in <module>
  File "<frozen importlib._bootstrap>", line 488 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 999 in exec_module
  File "<frozen importlib._bootstrap>", line 935 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1331 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1360 in _find_and_load
  File "C:\Users\pc\Documents\aaaa\uv_test\.venv\Lib\site-packages\texterrors\__init__.py", line 1 in <module>
  File "<frozen importlib._bootstrap>", line 488 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 999 in exec_module
  File "<frozen importlib._bootstrap>", line 935 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1331 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1360 in _find_and_load
  File "<string>", line 1 in <module>

Are you using a uv managed Python version?

Yes

[jjhelmus]

This error also occurs when using CPython 3.12 (3.12.10) installed from Python.org. This seems like it may be an issue in upstream CPython that the conda-forge / Anaconda build happened to fix.

[jjhelmus]

Moving this to python-build-standalone as it is an issue with the CPython build provided by uv rather than uv itself.