Are you sure?

use strict;
use warnings;

foreach my $foo (1..10 ) { print $foo }
foreach my $foo (1..10 ) { print $foo }
__END__
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I'm not seeing any errors or warnings using Perl's from 5.6.2 -> 5.9.0. I would be surprised if it would produce any warnings or errors, as this is an idiom that I use myself from time to time (without warnings, I might add).

Liz