There is no “nl”, it is “nl-in” and “nl-out”

nl-out is still not documented

doc/Type/IO.pod6

@@ -141,7 +141,7 @@ my $name = prompt("Hi, what's your name? ");
 
 =for code :skip-test
 my $fh = open(IO::Path() $path, :$r, :$w, :$a, :$rw,
-              :$bin, :$enc, :$nl, :$chomp)
+              :$bin, :$enc, :$nl-in, :$chomp)
 
 Opens the C<$path> (by default in text mode) with the given options,
 returning an L<IO::Handle> object.
@@ -231,15 +231,15 @@ This is because one needs to specify a specific unicode encoding, e.g.
 
 =head3 Newline options
 
-=item end-of-line (EOL) marker, C<:nl>
+=item end-of-line (EOL) marker, C<:nl-in>
 
 The marker used to indicate the end of a line of text.  Only used in text
 mode.  Defaults to "EOL", which implies accepting any combination of C<"\n">,
 C<"\r\n"> or C<"\r"> or any other Unicode character that has the C<Zl>
 (Separator, Line) property.
 
     # explicitly use CR-LF as EOL character
-    my $fh = open("path-to-file", nl => "\r\n");
+    my $fh = open("path-to-file", nl-in => "\r\n");
 
 =item chomp mode, C<:chomp>