use assign::Test;
my $want = <<'...';
use strict;
use warnings;
use assign::0;
my $___1001 = [];
my ($a1, $b1);
$a1 = $___1001->[0];
$b1 = $___1001->[1];
#line 6
warn "warn line 8";
my $___1002 = [];
my ($a2, $b2);
$a2 = $___1002->[0];
$b2 = $___1002->[1];
#line 16
die "die line 18";
...
is + assign::0->debug("$t/line-numbers.pl"), $want,
    "assign::0->debug() works";