Function glob_walk_root 

fn glob_walk_root(pattern: &Path) -> &Path

Given a glob pattern, walk up the path tree until we find a component that contains no glob metacharacters (*, ?, [). The result is a concrete directory (or .) suitable as a WalkDir root.

For example:

• target/**/*.txt → target/
• target/release/foo-* → target/release/
• *.tar.gz → .