This is specifically regarding URIs of the form "file:path/to/somewhere"

We should provide a correct error message for now, and in case pathlib or we decide to support parsing relative path uri's we can switch, see:

• 662c294#r123906140 expecting support for file:path/file.txt
• GH-107465: Add pathlib.Path.from_uri() classmethod. python/cpython#107640

Originally posted by @ap-- in #108 (comment)