The thing is that listing the attributes would not necessary create a unique path to the element. Using the position is the only way that's always garanteed to work. If you look at the example below, you will see that indeed several distinct results have the same complete_path output.

So for your specific case, the solution is to actually write code that does what you want. Or at least to cut-n-paste the code below ;--) Basically it subclasses XML::Twig::Elt to add the complete_xpath method, that does what you want (you could also do it without subclassing, by just calling a function on the element).

#!/usr/bin/perl 

use strict;
use warnings;

use XML::Twig;

my $xpath_arg= '//*[@keep="1"]';

my $twig= XML::Twig->new( elt_class => 'my_elt')->parse( \*DATA);
my $twig_root= $twig->root;

my @res = $twig_root->get_xpath($xpath_arg);

foreach ( @res ) {
    print $_->complete_path . " : ";
    print $_->text . "\n";
}

package my_elt;
use base 'XML::Twig::Elt';

sub complete_path
  { my( $elt)= @_;
    return '/' . join( '/', map { $_->tag_desc } reverse $elt->ancesto
+rs_or_self);
  }

sub tag_desc
  { my( $elt)= @_;
    my %atts= %{$elt->atts};
    my $atts= %atts ?  '[' . join( " ", map { qq{$_="$atts{$_}"} } sor
+t keys %atts) . ']' : '';
    return $elt->tag . $atts;
  }

package main;
__DATA__
<doc>
  <elt att1="1" keep="1">
    <elt2 att2="2" keep="1">foo</elt2>
    <elt2 att2="2" keep="0">bar</elt2>
  </elt>
  <elt att1="1">
    <elt2 att2="2" keep="0">foo2</elt2>
    <elt2 att2="2" keep="1">bar2</elt2>
  </elt>
  <elt att1="1" keep="1">
    <elt2 att2="2" keep="1">foo3</elt2>
    <elt2 att2="2" keep="1">bar3</elt2>
  </elt>
</doc>
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