uv sync consistently returns error in combination with local repository

[MaartendeRuyter]

Summary

When running uv -sync --upgrade in combination with a local repository, broken pipe errors keep on popping up.
After rerunning uv -sync --upgrade a number of times eventually the sync finishes successfully. See below the terminal output

Pyproject.toml
[[tool.uv.index]]
url = "http://localhost:8080/"
default = false

Terminal Output
uv sync --upgrade
⠙ bunnet==1.3.0 error: Failed to fetch: http://localhost:8080/lazy-loader/
Caused by: error sending request for url (http://localhost:8080/simple/lazy-loader/)
Caused by: client error (SendRequest)
Caused by: error writing a body to connection
Caused by: Broken pipe (os error 32)
❯ uv sync --upgrade
⠙ location-loader==1.1.5 error: Failed to fetch: http://localhost:8080/mongoengine/
Caused by: error sending request for url (http://localhost:8080/simple/mongoengine/)
Caused by: client error (SendRequest)
Caused by: error writing a body to connection
Caused by: Broken pipe (os error 32)
❯ uv sync --upgrade
⠸ python-dotenv==1.0.1
Resolved 98 packages in 2.79s
Prepared 2 packages in 66ms
Uninstalled 2 packages in 14ms
Installed 2 packages in 23ms

• anyio==4.8.0

• anyio==4.9.0

• geo-datagarden-models==1.1.7

• geo-datagarden-models==1.1.8

Platform

mac OS15 M2

Version

uv 0.6.6

Python version

3.13

[charliermarsh]

I think we'd need a more complete reproduction to help here, like a GitHub repo we can clone and a series of steps we can run to reproduce the error ourselves.

[MaartendeRuyter]

Ok I will try and make a repo where this can be reproduced