In order to avoid the wrong caller package issue, you can create a wrapping sub for open in the caller package and jump there using goto &$sub which overwrites the current stack frame. Something similar to the following code: 
package MyOpen;
use Carp ();
use Data::Dumper;
use 5.010;

my %cache;

BEGIN {
    *CORE::GLOBAL::open = sub {
        my $pkg = caller;
        my $sub = $cache{$pkg} //= do {
            my $code = <<EOS;
package $pkg;
sub {
    my \$r = CORE::open \$_[0], \@_[1..\$#_];
    Carp::cluck(Data::Dumper::Dumper(\@_));
    return \$r;
}
EOS
            eval $code or die "Bad sub: $@";
        };
        goto &$sub;
    };
}


package main;

open $fh, '>&', 'STDOUT';
open FOO, ">", "/tmp/FOO";

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In reply to Re^5: Track open file handles by salva
in thread Track open file handles by shmem

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