sub default question

Hi All,

https://github.com/rakudo/rakudo/blob/main/src/core.c/Proc.rakumod
232: multi sub run(*@args where .so, :$in = '-', :$out = '-', :$err = '-',

Here is my confusion.  The above sets
    :$in = '-', :$out = '-', :$err = '-',
to "-" as the default.

But if you leave
    :$out  and :$err
off the run line, STDOUT and STDERR do not
get captured and are sent to the console.

My confusion is when you leave a parameter
off that is set with a default in the sub
deceleration, I thought the sub declaration
was used.

What am I missing?

Yours in Confusion,
-T