Thanks for your advice. My initial question was more of a generic nature, of how to easily run tests in several platforms. But narrowing it down to my current problem here is the code in question

eval {
    $sfr = WWW::Salesforce::Report->new(
        file => "t/report.csv",
    );
   $data = $sfr->get_report();
};
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the part that fails in the get_report sub is as follows:

sub get_report () {
  ...

        open my $fh,"<", $self->{ file } or
            croak "Could not open $self->{ file } : $!";
        
        $res = "";
        while( <$fh> ) {
            $res .= $_;
        }
   ...
}
[download]

report.csv is a file that exists in the test directory or "WWW-Salesforce-Report-0.01/t"

$self->{ file } is assigned in new to the file name passed in "file"