ts.option with default None cause Missing Option in click

Hi, it's been a while! I am glad to see the project is still around and maintained!

I've recently hit a strange error, which I haven't been able to find the root cause of yet.

The problematic option looks like this

engine_name: str = ts.option(default="", converter=empty_str_to_none,help="engine")

Here is a reproduction of the error repository

to reproduce, simply run

uv sync --all-groups
uv run repro execute

Thank you, I'll let you know if I can find the root cause earlier than I get the answer.

Edited Oct 30, 2025 by Jan Gazda