Summary

uv publish --check-url fails with

error: Failed to query check URL
  Caused by: Unsupported `Content-Type` "text/plain" for https://gitlab.example.org/api/v4/projects/1234/packages/pypi/simple/example-package/. Expected JSON or HTML.

in GitLab when the package doesn't exist. It should just upload the package in that case and not fail.

Platform

Linux 7.0.5-arch1-1 x86_64 GNU/Linux

Version

uv 0.11.14 (3fdfdc7 2026-05-12 x86_64-unknown-linux-gnu)

Python version

Python 3.13.12