Somewhat of a side discussion, but these aren't the only issues you can have when using uv-build.
While it's stable now, it expects certain directory layouts and can only be used on pure Python projects. If you need anything else, you are better off using hatchling anyway, which used to be the default even for uv.
This is also why some of your old uv-based projects might build fine and the same code won't build in a modern uv project; they switched the default.
Here's a thing directly from the authors:
While the backend supports a number of options for configuring your project structure, when build scripts or a more flexible project layout are required, consider using the hatchling build backend instead.