Feedback from Antoine on IRC about my syntax proposal: “The "**" meaning is not really universal like other quantifiers are. [...] (also, it would be quite harder to implement, I think)”

That and the compat issue makes me go in favor of a new function.

I’m not sure glob is the right place: when you use glob.glob, the search is rooted in the current directory, and you may have sub-directories in your pattern, e.g. 'Lib/*/__main__.py'.  A function meaning “look for this file pattern recursively” would be IMO more at home in fnmatch.