[Interest] [OS X/MacPorts] parallel qt4 and qt5 installs

[René J.V. Bertin]

Hi,

My main work environment is under OS X, based on MacPorts. It is currently not possible with that framework to have Qt4 and Qt5 installed in parallel; it's one or the other, installed into ${prefix} (usually /opt/local).

I don't know why the Qt4/5 port maintainer didn't set things up from the get-go to allow parallel installations, so I'd like to make a start with enabling that, at least for Qt4 and probably "simply" using qtchooser as is also done under Linux.

I haven't found a lot of information about qtchooser, so I'm hoping I can get some advice on here on how best to proceed.
If in anyway possible, I'd like to do this in a way that doesn't force me to rebuild all my Qt4 (and KDE4) applications at once.
I suppose that would oblige me to put symlinks from the current shared libraries' install locations in ${prefix} to wherever I decide to put the new version - can that be automated?
I also presume that one cannot have that kind of symlinks for both Qt4 and Qt5, or can the library files actually live together in the same directory (regardless of whether they're frameworks or ".dylibs")?

The current Qt4 Portfile can be consulted here: https://trac.macports.org/browser/trunk/dports/aqua/qt4-mac/Portfile (yup, that's tcl :) )

Thanks in advance!

René