Summary

Issue Description

0.5.27 of uv changed the behavior for by hand creating an virtual environment and trying to install packages into it.

Error is:
'''
##[error] > [builder 7/15] RUN uv pip sync --no-cache-dir -r requirements.txt:
##[error]0.312 error: No virtual environment found; run uv venv to create an environment, or pass --system to install into a non-virtual environment
'''

Running the example code with uv==0.5.26 works fine.

The Changelog for 0.5.27 does not list any differences which could explain this error.

Steps to reproduce

(Docker):

ARG PYTHON_VERSION=3.10

# === builder stage ===
FROM python:${PYTHON_VERSION}-slim AS builder

ENV PYTHONDONTWRITEBYTECODE=1
ENV PYTHONUNBUFFERED=1

WORKDIR /detectors

RUN pip install uv==0.5.27

RUN uv --version
RUN uv venv /opt/venv --python ${PYTHON_VERSION} --no-project

ENV PATH="/opt/venv/bin:$PATH"

# install requirements.txt
COPY requirements.txt .
RUN uv pip sync --no-cache-dir -r requirements.txt # <<< Error

Platform

docker/Linux

Version

0.5.27

Python version

3.10