MacPorts missing links

[Ryan Schmidt]

> On Sep 11, 2016, at 5:37 PM, Lawrence Velázquez <larryv at macports.org> wrote:
> 
>> On Sep 11, 2016, at 6:33 PM, Ryan Schmidt <ryandesign at macports.org> wrote:
>> 
>>> On Sep 11, 2016, at 5:22 PM, Ryan Schmidt <ryandesign at macports.org> wrote:
>>> 
>>>> On Sep 11, 2016, at 4:57 PM, David Epstein <David.Epstein at warwick.ac.uk> wrote:
>>>> 
>>>> I do not understand the issues involved and their ramifications, so I may be saying something stupid, but it seems to me, as a naive user, that this reveals a rather bad design fault in “port select”. An "available version" should either be “none” or the true name of an installed port. I realize that resources  to fix things are scarce, but could the ability to choose a random name at least be acknowledged as bad practice, and could a ticket be provided for work to be done so that this behaviour becomes impossible?
>>> 
>>> I think we don't consider this to be a design fault, but a feature. In other words, it was not a mistake that the select group entry can differ from a port; it was a deliberate decision to allow that. As has been pointed out, we want to be able to select things that are part of macOS and are not provided by a port.
>>> 
>>> I agree that some of the select group entry names we've chosen are not optimal in the way in which they differ from the name of the port they provide. It might be a pain to fix that at this late date.
>> 
>> Maybe we could also display the name of the port, if any, that provides each select group entry.
> 
> That's an idea, although then entries like "python27-apple" would appear to come from "python_select", which would be a little weird.

Provide a way for a port to override it, so that we can fix that to say that it comes from macOS whatever.version.