Why did it not select the :basename candidate??

gistfile1.txt

Cannot resolve caller new(IO::Path:U: :basename(Str)); none of these signatures match:
    (IO::Path: $path, :$CWD!, *%_ --> IO::Path)
    (IO::Path: $path, IO::Spec:D :$SPEC!, *%_ --> IO::Path)
    (IO::Path: :$basename!, :$dirname = "", :$volume = "", :$CWD = { ... }, IO::Spec:D :$SPEC = { ... }, *%_)
    (IO::Path: Str:D $path, *%_ --> IO::Path)
    (IO::Path: $path, *%_ --> IO::Path)