Install old version PyQt4 on a mac by compiling the source

[Phil Thompson]

On 13/07/2021 21:39, Felix Voigt wrote:
>> On 10. Jul 2021, at 12:29, Phil Thompson <phil at riverbankcomputing.com> 
>> wrote:
>> 
>> On 10/07/2021 11:16, Felix Voigt wrote:
>>>> On 9. Jul 2021, at 10:09, Phil Thompson 
>>>> <phil at riverbankcomputing.com> wrote:
>>>> On 08/07/2021 19:37, Felix Voigt wrote:
>>>>> Hello everyone,
>>>>> today I tried the same with PyQt5 with the following results.
>>>>> The configure process succeeded:
>>>>> cd ~/documents/tmp/PyQt5-5.15.4
>>>>> ~/.pyenv/versions/2.7.18/bin/python2.7 configure.py --qmake
>>>>> /usr/local/Cellar/qt at 5/5.15.2/bin/qmake
>>>>> --sip=/Users/felixvoigt/.pyenv/versions/2.7.18/bin/sip --verbose
>>>>> The make process failed:
>>>>> make
>>>>> -> In file included from
>>>>> /Users/felixvoigt/documents/tmp/PyQt5-5.15.4/sip/QtCore/qsocketnotifier.sip:26:
>>>>> /usr/local/Cellar/qt at 5/5.15.2/lib/QtCore.framework/Headers/qsocketnotifier.h:117:35:
>>>>> error: constexpr function never produces a constant
>>>>>     expression [-Winvalid-constexpr]
>>>>>   Q_DECL_CONSTEXPR_NOT_WIN bool isValid() const noexcept { return
>>>>> *this != QSocketDescriptor(); }
>>>>>                                 ^
>>>>> /usr/local/Cellar/qt at 5/5.15.2/lib/QtCore.framework/Headers/qsocketnotifier.h:117:75:
>>>>> note: undefined function 'operator!=' cannot be used
>>>>>     in a constant expression
>>>>>   Q_DECL_CONSTEXPR_NOT_WIN bool isValid() const noexcept { return
>>>>> *this != QSocketDescriptor(); }
>>>>>                                                                     
>>>>>     ^
>>>>> /usr/local/Cellar/qt at 5/5.15.2/lib/QtCore.framework/Headers/qsocketnotifier.h:124:42:
>>>>> note: declared here
>>>>>   friend Q_DECL_CONSTEXPR_NOT_WIN bool operator!=(QSocketDescriptor 
>>>>> lhs,
>>>>> 1 error generated.
>>>>> Any ideas how to fix it?
>>>>> Kind regards
>>>>> feli_x
>>>> As the error is referring to Qt source code and not SIP generated 
>>>> code then the problem may be your version of Xcode.
>>>> Phil
>>> Hello Phil and thanks,
>>> meanwhile I updated my xcode from beta 9.0 to 11.3.1.
>>> I managed to configure pyqt5 via:
>>> ~/.pyenv/versions/2.7.18/bin/python2.7 configure.py --qmake
>>> /usr/local/Cellar/qt at 5/5.15.2/bin/qmake
>>> --sip=/Users/felixvoigt/.pyenv/versions/2.7.18/bin/sip —verbose
>>> Although there was a warning, which I neglected:
>>> Project WARNING: Qt requires at least version 10.14 of the platform
>>> SDK, you're building against version 10.13. Please upgrade.
>>> The make process succeeded, there were also many warnings, which are
>>> too many to store them I thought.
>>> Finally:
>>> make install
>>> Now, my next problem is, if I start the python program, the line 
>>> "from
>>> PyQt5 import QtCore, QtGui” gives an error message:
>>> ~/.pyenv/versions/2.7.18/bin/python2.7 test.py
>>> Traceback (most recent call last):
>>> File "test.py", line 1, in <module>
>>>   from PyQt5 import QtCore, QtGui
>>> ImportError: No module named sip
>>> I tried including the folder
>>> /Users/felixvoigt/.pyenv/versions/2.7.18/bin in my PATH, which was 
>>> not
>>> a solution.
>>> Does somebody know how to configure sip correctly such that it can be
>>> found by pyqt5?
>> 
>> https://www.riverbankcomputing.com/static/Docs/PyQt5/installation.html#building-the-sip-module
>> 
>> Phil
> 
> Hello again,
> thanks for the answer.
> If I take the PyQt5_sip-12.9.0.tar.gz version downloaded from
> https://pypi.org/project/PyQt5-sip/#files, I obtain the following:
> After the commands
> cd ~/documents/tmp/PyQt5_sip-12.9.0
> ~/.pyenv/versions/2.7.18/bin/python2.7 setup.py  build
> 
> the following error results:
> In file included from ./sipint.h:26:
> ./sip.h:28:2: error: "This version of SIP requires Python v3.5 or 
> later"
> #error "This version of SIP requires Python v3.5 or later”
> 
> Is there a version of PyQt5_sip which is applicable to python2.7? And
> by the way, do I need sip or PyQt5_sip, and what is the difference?
> Sorry for many questions,
> best regards

My apologies (Python v2 is no longer supported), you probably need to 
use SIP v4 (also no longer supported) which you can find here...

https://www.riverbankcomputing.com/software/sip/download

Phil