`uv pip install -r requirements.txt` flakiness with `datashader` and `llvmlite` packages

[chrisrodrigue]

Summary

This requirements.txt lists all packages in the WinPython distribution, which is an open source alternative to Anaconda for the Windows platform.

There was some flakiness when I attempted to install these packages into a venv (pyvenv.cfg) using the uv pip install -r requirements.txt command.

I am reporting the errors that I saw here if they would be helpful to make uv pip install more robust. If the errors can't be duplicated and/or fixed then feel free to close this issue!

1st attempt

(WinPython) C:\Users\Chris\OneDrive\Downloads\Winpython64-3.13.2.0slimb3\WPy64-31320b3>uv pip install -r requirements.txt
  × No solution found when resolving dependencies:
  ╰─▶ Because datashader==0.16.3 has an invalid package format and you require datashader==0.16.3, we can conclude
      that your requirements are unsatisfiable.

      hint: The structure of `datashader` (v0.16.3) was invalid:
        Failed to read from zip file

2nd attempt

(WinPython) C:\Users\Chris\OneDrive\Downloads\Winpython64-3.13.2.0slimb3\WPy64-31320b3>uv pip install -r requirements.txt
  × No solution found when resolving dependencies:
  ╰─▶ Because llvmlite==0.44.0 has an invalid package format and you require llvmlite==0.44.0, we can conclude that
      your requirements are unsatisfiable.

      hint: The structure of `llvmlite` (v0.44.0) was invalid:
        Failed to read from zip file

3rd attempt

Retrying the command a third time seemed to work and installed all 495 packages from requirements.txt into the venv.

Additional observations

The latest version of pip was also installed into the venv (for a total of 496 packages), even though pip was not listed in requirements.txt or present inside the venv as a seed package. Is this behavior correct?

Possibly related issues

• Unable to install/build the llvmlite package #6281
• Tracking issue: uv backtracks on the wrong package #8157
• Installation fails for statsforecast due to llvmlite Python version constraint #9413
• Error while installing llvmlite on Windows #9898

Platform

Windows 11 x86_64

Version

uv 0.6.1

Python version

Python 3.13.2

[konstin]

Are you using PyPI or an alternative index?

[chrisrodrigue]

Are you using PyPI or an alternative index?

Nexus PyPI proxy.

Want me to try clearing the cache and re-running with -v or -vv to see if I can get some more helpful data?

[konstin]

This error looks like a problem where we are not applying our retry strategy to the async zip reader.