[BUG] Remote container proxy blocks releases.astral.sh:443, preventing uv from downloading Python versions.

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When running CC on claide.ai connected to github, the remote container proxy blocks releases.astral.sh:443, preventing uv from downloading Python versions. Specifically, the latest version of python 3.14 uv comes with is 3.14.0rc2 (currently the latest is 3.14.5). CC claims "Proxy blocks all sources that have it (astral, deadsnakes, python.org). Only 3.14.0rc2 (uv) available."

What Should Happen?

uv venv --python 3.14 installs a stable version and not a release candidate

Error Messages/Logs

`python3.14` available via apt. Installing, then check exact version.

All external package sources blocked by proxy — `releases.astral.sh`, `launchpadcontent.net`, `python.org` all 403. Only Ubuntu's default apt mirror works.

Only source for `python3.14` is deadsnakes PPA — also blocked. Container proxy blocks everything except Ubuntu default repos and PyPI/npm/crates.

**Bottom line:** No path to stable Python 3.14.x in this container. Proxy blocks all sources that have it (astral, deadsnakes, python.org). Only `3.14.0rc2` (uv) available.

This is a container network policy limitation. Options:
1. Proceed with `3.14.0rc2` and note pydantic may have issues
2. Use `3.13` from default Ubuntu repos (stable, pydantic works)
3. File issue with Anthropic to allow `releases.astral.sh` or deadsnakes

Steps to Reproduce

1. Connect claude.ai/code to a github repo with a pyproject.toml which includes

``
[project]
requires-python = ">=3.14"
``

1. Tell claude to work with uv
2. Ask claude what version of python it has installed
3. Ask to upgrade to 3.14.5 with uv venv --python 3.14.5

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.195 (Claude Code)

Platform

Other

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

_No response_