> `uv lock` fails if your lock file has a mismatch

Now you seem even more confused. Do you mean `uv sync` will fail? `uv lock` is literally the command you run when there's a mismatch between pyproject.toml and uv.lock to update uv.lock. That's why it's called lock.

Here's a full reproducer: https://gist.github.com/remram44/21c98db9a80213b2a3a5cce959d...

Check out branch "previous-blog". Run `docker build . -t uvtest`. You will see that it builds with no error, and if you run `docker run uvtest cat /app/uv.lock`, you will see that the uv.lock in the image is NOT the one in the repo. It has been updated silently, which is what gchamonlive and myself pointed out.

Now check out branch "master". Run `docker build . -t uvtest` again. You will see `error: The lockfile at `uv.lock` needs to be updated` which is what you say always happened.