Qt5 port group

[Marcus Calhoun-Lopez]

> On May 9, 2018, at 11:07 AM, Ryan Schmidt <ryandesign at macports.org> wrote:
> 
> My understanding of the fact that they conflict is that there is some latest version of Qt that is compatible with each version of macOS, and that by using the qt5 portgroup, one automatically receives that version. However, in practice, that does not appear to be the case. I see build failures of my Qt-using ports on some macOS versions because the chosen version of Qt is not compatible with that version of macOS.

I am aware of one instance of the wrong Qt component being installed for a particular system
(https://trac.macports.org/ticket/55651).
I am afraid I am unaware of any others.
Do you happen to remember which ones fail?

As a side note, I should have taken care of ticket #55651 by now, but QtWebEngine is a bit of corner case.
It does not seem to be widely used based on the number of Portfiles that use it.

-Marcus