vars_ok ignores the final missing var

[petdance]

Here's my lib/foo.pm

package foo;

my $scalar;
my %hash;
my @array;

sub foo {
    my $foo_scalar;
    my %foo_hash;
    my @foo_array;
    my @foo9;
}

1;

and here's my foo.t

#!/usr/bin/perl

use warnings;
use strict;
use 5.010;
use experimental 'signatures';

use Test::More tests => 1;

use Test::Vars;

vars_ok( 'lib/foo.pm' );

exit 0;

And when I run it, I get three errors, not four.

$ prove foo.t
[11:15:13] foo.t .. 1/1
#   Failed test 'lib/foo.pm'
#   at foo.t line 13.
# $foo_scalar is used once in &foo::foo at lib/foo.pm line 8
# %foo_hash is used once in &foo::foo at lib/foo.pm line 8
# @foo_array is used once in &foo::foo at lib/foo.pm line 10
# Looks like you failed 1 test of 1.
[11:15:13] foo.t .. Dubious, test returned 1 (wstat 256, 0x100)
Failed 1/1 subtests
[11:15:13]

Test Summary Report
-------------------
foo.t (Wstat: 256 Tests: 1 Failed: 1)
  Failed test:  1
  Non-zero exit status: 1
Files=1, Tests=1,  0 wallclock secs ( 0.02 usr  0.01 sys +  0.06 cusr  0.01 csys =  0.10 CPU)
Result: FAIL

If I change foo.pm to only have my $foo_scalar; in the sub, the test passes.