use File::Find::Rule;
foreach my $path ( @project_paths ) {
    my $rule = File::Find::Rule->file->name('*.xml')->start( $path );
    if ( my $xml_file = $rule->match ) {
        print "The first XML file under dir '$path' is '$xml_file'\n";
    }
    else {
        print "No XML files found under dir '$path'\n";
    }
}