[PyQt] PyQt on OSX Snow Leopard notes

William Kyngesburye woklist at kyngchaos.com
Fri Sep 11 16:00:39 BST 2009

On Sep 11, 2009, at 8:57 AM, Phil Thompson wrote:

> On Fri, 4 Sep 2009 09:13:08 -0500, William Kyngesburye
> <woklist at kyngchaos.com> wrote:
>> For those trying this, here's what I found so far:
>> - gcc compiles 64bit by default now, which will cause problems with
>> the 32bit-only Qt (unless you are using Qt Cocoa).  Configure SIP
>> universal so you get a 32bit SIP (the extra PPC code is harmless,
>> except that PyQt will take longer to compile and be larger than
>> necessary).  If you want 32bit-only or 32+64bit intel, you need to
>> edit siputils.py and change the unicflags and unilflags lines
>> appropriately.
>> - the macx-g++ Qt mkspec is meant to run the current gcc version,
>> which is now 4.2.  But there is also a specifically macx-g++42
>> mkspec.  I figured macx-g++ should agree more with Qt, which was  
>> built
>> with gcc 4.0, so I edited it to run 4.0.  I don't know if it's really
>> a problem anywhere down the line.  Maybe there should be a macx-g++40
>> now.  But I don't know how to select a mkspec in the PyQt
>> configuration (I haven't looked).
>> - the python 2.6 executable is 32+64bit now, and will run 64bit by
>> default. This is a problem with pyuic4, which is a shell script which
>> runs a python script (with pythonw).  At first I thought to use the
>> arch command in pyuic4 shell script to run pythonw in 32bit mode, but
>> apparently the arch command is broken and pythonw would still run
>> 64bit.  So I ended up creating a stripped copy of pythonw in /usr/
>> local/bin with ditto:
>> sudo ditto -arch i386 /usr/bin/pythonw2.6 /usr/local/bin/pythonw32
>> and running that from the pyuic4 script.  If any of your PyQt-based
>> applications run from python, they'll have to use this also.  Unless,
>> of course, you use Qt Cocoa and compile PyQt 64bits.
> Using Python v2.6.2 from python.org, and after recompiling Qt, then  
> PyQt
> builds as normal.
Because it's 32bit only.

> Until Qt properly supports Snow Leopard I think I'll leave things as  
> they
> are.
It's not so much a problem of Qt supporting Snow (yes, the mkspec  
problem, but it seems to be minor), but supporting OSX 64bit, which  
covers both Leopard AND Snow.  The standard Carbon-based Mac Qt will  
never be 64bit.  Qt Cocoa is 64bit (I have yet to try it out).

And there is now the extra 64bit-ness of Python in Snow now, which  
causes trouble with Python-based software.  People WILL update to Snow  
and WILL (and have already) have problems compiling PyQt.

Since Qt Cocoa may take a while to be fully functional and in common  
use, PtQt at least needs some way to deal with a 64bit Python  
executable (use the arch command where python/pythonw executed when  
built for Qt carbon).

Note: I just figured out the problem with the arch command.  It's not  
broken.  There are 2 copies of the python and pythonw executables: in / 
usr/bin and in the Python framework.  The /usr/bin exe's are not  
symlinks to the framework, and have different file sizes.  For some  
reason the /usr/bin exe's don't work with arch, but the framework  
exe's do.  /usr/bin/python2.6 and /usr/bin/pythonw2.6 ARE symlinks to  
the framework.

William Kyngesburye <kyngchaos*at*kyngchaos*dot*com>

"The beast is actively interested only in now, and, as it is always  
now and always shall be, there is an eternity of time for the  
accomplishment of objects."

- the wisdom of Tarzan

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