How can variant B imply variant A?

[Jeremy Lavergne]

> However, I'm still left with a tiny follow up (in case that it is
> doable without too much hassle). Can the following be done (below is
> just "pseudocode")?
> 
>    variant wxt description "Enable wxWidgets" {
>        if {![variant_isset wxwidgets] && ![variant_isset wxwidgets_devel]} {
>            if {[port_isinstalled wxWidgets-devel]} {
>                variant-enable wxwidgets_devel
>            } else {
>                variant-enable wxwidgets
>            }
>        }
>    }

Are the variants actually going to change the installed files when using -devel versus not? I'd make separate ports, each cleaning depending on the version of wxwidgets they need. This is easily achieved with the new subports mechanism, to avoid having to repeat most of the Portfile code.