Proper way to add $destroot/opt/local/libexec/perl5.20 to PATH

[Mojca Miklavec]

Hi,

The command
    sudo port -v -t test p5.20-catalyst-helper-authdbic
fails because it tries to call catalyst.pl directly which is otherwise either in
    /opt/local/bin/catalyst.pl-5.20
or in
    /opt/local/libexec/perl5.20/catalyst.pl
(and probably hidden inside $destroot while testing)

What's the proper workaround for this? See
    https://rt.cpan.org/Public/Bug/Display.html?id=62844

Thank you,
    Mojca