I am using File::Spec to make a factory method portable as follows:

sub create {
    my $class = shift;
    require File::Spec;
    my @path = split(/\:\:/,$class);
    my $file = pop @path;
    $file .= ".pm";
    my $fp = File::Spec->catfile(@path, $file);
    require $fp;
    return $class->new(@_);
}
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I am testing this on windows although the code is destined to be a CGI script. The libary could be used in several ways, not just CGI scripts hence the importance of portability. Now when I run my CGI script on windows in taint mode I get the following error:

Insecure dependency in require while running with -T switch at .... 
[the line "require $fp"]
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Now I am using CGI::Safe so I thought the path should be untainted. I have looked inside the File::Spec module but I cannot actually see where it is going outside the system to look at the filesystem.