[Qt-interest] Switching Qt Installation

[Andreas Pakulat]

On 13.10.09 11:45:44, Frank Neuhaus wrote:
> On Tue, Oct 13, 2009 at 11:04 AM, Stephen Jackson <spjackson42 at gmail.com> wrote:
> > On Mon, Oct 12, 2009 at 8:41 AM, Frank Neuhaus wrote:
> >> I installed Qt 4.5.2. with my Linux Distribution (Fedora)'s packet
> >> manager. Now I want to compile the latest git version of Qt creator,
> >> which unfortunately requires 4.6.0. I downloaded the 4.6.0 tech
> >> preview edition, compiled and installed it. It installed into
> >> /usr/local/Trolltech/Qt-4.6.0-tp1/.
> >> The problem is that even when explicitly calling
> >> /usr/local/Trolltech/Qt-4.6.0-tp1/bin/qmake, qmake generates Makefiles
> >> that include /usr/include/QtSomething, which obviously belong to my
> >> old Qt 4.5.2 installation. Environment variables such as QTDIR appear
> >> to be ignored.
> >> How can I tempoarily change my installation to 4.6.0 to compile Qt creator?
> >>
> >
> > I haven't used 4.6 or tried to compile Qt Creator. However, specifying
> > the path to qmake (or setting PATH) is all I need to do to switch
> > between Qt versions for building application code. As I understand it,
> > that is all you are supposed to do.
> >
> > If that isn't working for you (as you indicate above), I suggest that
> > you check whether this is something specific to building Qt Creator,
> > and also whether you have any environment variables pointing at
> > /usr/include/QtSomething. Do you run "configure" for building Qt
> > Creator? Is that where it is going wrong?
> >
> > I hope this gives you some clues.
> 
> I believe the problem is not specific to Qt Creator. Its a "standard
> Qt program", i.e. it doesn't require configure or anything. Just qmake
> followed by make suffices.
> What do you mean with specifying the path to qmake? My /usr/bin
> contains a symbolic link to my 4.5.2 qmake... Even when i exchange
> that link by a link to the 4.6 qmake, it does not work. That is - the
> proper qmake is called when I type qmake (checked that with qmake -v),
> but it keeps using the include directories in /usr/include/QtGui and
> so on. I can see that when I type make and I look at the actual
> compiler calls - they contain -I/usr/include/QtGui etc.
> 
> How does qmake determine which include directories to use?

Its compiled into the binary. You can see the path it'll use by simply
running qmake -query. These paths can be adjusted by qt.conf file with a
specific format in QT_INSTALL_PREFIX.

Andreas
 
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