`uv pip compile` ignores private index credentials if `pyproject.toml` is not in the current directory

[ketozhang]

Summary

My colleague (@sarmen-t) and I encountered that by following https://docs.astral.sh/uv/concepts/indexes/#providing-credentials-directly for injecting index credentials, uv pip compile $SRC_FILE fails to use credentials if $SRC_FILE is not exactly pyproject.toml (i.e., pyproject.toml cannot live in a subdirectory of CWD).

Here's a MWE (index url is faked)

[project]
name = "projectA"
version = "0.1.0"
description = "Add your description here"
readme = "README.md"
requires-python = ">=3.12"
dependencies = ['internal-package']

[tool.uv.sources]
internal-package = { index = "internal-proxy" }

[[tool.uv.index]]
name = "internal-proxy"
url = "http://internal-proxy.example.com/simple/"
explicit = true

Contents of a multi-projects directory:

$ ls
projectA  projectB  README.md
$ ls projectA
src  pyproject.toml

Fail case:

--no-cache is added to force auth & downloading from remote index.

$ export UV_INDEX_INTERNAL_PROXY_USERNAME=public
$ export UV_INDEX_INTERNAL_PROXY_PASSWORD=koala
$ uv pip compile --format pylock.toml --no-cache projectA/pyproject.toml
error: Failed to fetch: `http://internal-proxy.example.com/packages/internal-package-3.3.1-py2.py3-none-any.whl`
  Caused by: HTTP status client error (401 Unauthorized) for url (http://internal-proxy.example.com/packages/internal-package-3.3.1-py2.py3-none-any.whl)

Successful alternatives:

$ cd projectA
$ uv pip compile --format pylock.toml --no-cache pyproject.toml

$ uv pip compile --format pylock.toml --no-cache --project projectA/ projectA/pyproject.toml

We can see from the last successful alternative that the issue is due to --project option which default to the CWD and is independent from $SRC_FILE. The error makes sense, but it is surprising that uv pip compile does not read the uv metadata table from the $SRC_FILE to obtain index metadata then subsequently its index credentials.

Platform

Darwin 24.6.0 x86_64

Version

uv 0.8.11 (Homebrew 2025-08-14)

Python version

Python 3.12.11