co-installable qt4-mac and qt5-mac step1 : qt4-mac +concurrent

[Ian Wadham]

On 15/12/2014, at 9:46 AM, René J.V. Bertin wrote:

> 'evening!
> 
> I finally got around to finishing up (or almost) my draft version for a qt4-mac port that can live alongside other (future) Qt port versions installed with the same approach: see https://trac.macports.org/ticket/46238 .
> 
> Related submissions:
> https://trac.macports.org/ticket/46239
> https://trac.macports.org/ticket/46240
> 
> Hope this helps! :)

It is a great start !!!  Thanks very much René!

Two things concern me about the proposed new directory structure, under "We get"
in ticket 46238.

   a) Traditionally you can install new or development versions of Qt "somewhere else"
        and point to your test or development version via environment variable $QTDIR.
        Does this presuppose a fixed hierarchy of directories and names under $QTDIR?
        If so, changing that hierarchy may cause problems.

  b) Shifting Qt libraries from ${prefix}/lib to ${prefix}/libexec/${qt_name}/lib might be
       a "no-op".  In the lib subdir (/opt/local/lib on my system), Qt libraries are installed
       as links.  For example, libQtCore.dylib, libQtCore.4.dylib, libQtCore.4.8.dylib and
       libQtCore.4.8.6.dylib all point to /opt/local/Library/Frameworks/QtCore.framework/QtCore,
       which in turn points to Versions/4/QtCore and THAT is actually a file described as
       Versions/4/QtCore: Mach-O 64-bit x86_64 dynamically linked shared library.

Maybe I am missing something.

Cheers, Ian W.