Problems with PyQt5 on Raspi 5 / Debian Bookworm

[Phil Thompson]

On 18/12/2023 13:28, ullix wrote:
> Thanks. I filed a bug report at Raspian:
> 
> https://bugs.launchpad.net/raspbian/+bug/2046806
> 
> ullix

I don't think that is going to help - why report something as a bug when 
it isn't a bug? If you followed the instructions then it will install. 
The problem is that doing so is too inconvenient in terms of time taken 
and packages needing to be installed.

What you should be asking for is somebody to make it convenient by 
creating Raspi wheels for everybody's benefit - or volunteering to do so 
yourself.

Phil

> Am 18.12.23 um 11:19 schrieb Phil Thompson:
>> On 18/12/2023 07:40, ullix wrote:
>>> Am 15.12.23 um 17:34 schrieb Phil Thompson:
>>>> On 15/12/2023 16:23, ullix wrote:
>>>>> I got the new Raspi 5 and tested a few things. I used pip to
>>>>> install/modify a dozen packages, and all worked except for *PyQt5.*
>>>>> 
>>>>> PyQt5 had been apt-installed as version 5.15.9, and worked in tests 
>>>>> of
>>>>> mine. But what failed was when trying to upgrade to 5.15.10. After
>>>>> closer instepction I apt-removed the apt-installed PyQt5, and tried 
>>>>> to
>>>>> pip-install that very same version. It failed with :
>>>>> 
>>>>>   Preparing metadata (pyproject.toml): started
>>>>>   Preparing metadata (pyproject.toml): finished with status 'error'
>>>>> 
>>>>> Full error report in attached file.
>>>>> 
>>>>> After reinstalling 'python3-pyqt5' via apt, it worked again.
>>>>> 
>>>>> Where is the problem: Raspi, Debian, pip, pyqt5?
>>>>> 
>>>>> ullix
>>>>> 
>>>>> 
>>>>> On Raspi 5 I used the default OS install:
>>>>> 
>>>>> 
>>>>>      Raspberry Pi OS with desktop
>>>>> 
>>>>>  * Release date: December 5th 2023
>>>>>  * System: 64-bit
>>>>>  * Kernel version: 6.1
>>>>>  * Debian version: 12 (bookworm)
>>>> 
>>>> pip is attempting to build from source and needs extra options to be 
>>>> specified. You also need a reasonably up to date pip. It's much 
>>>> easier to use pip to install sip and PyQt-builder and download the 
>>>> sdist, then run sip-install in the untarred sdist.
>>>> 
>>>> Phil
>>> 
>>> 
>>> Thanks, but I don't understand what the consequences of your 
>>> statement
>>> are. I also believe the problem indicates a broader problem.
>>> 
>>> Debian 12 (bookworm), the basis for the current Raspberry Pi OS, is
>>> drawing its conclusions from the success of Python and are now
>>> blocking the possibility of changing the Python installation of the 
>>> OS
>>> by pip. (I know you can break this by deleting file file
>>> 'EXTERNALLY-MANAGED' of pip-install with flag '--break-system-files',
>>> but this is defeating the purpose of this blocking).
>>> 
>>> They now direct everyone towards a venv install. This works, though 
>>> it
>>> requires extra steps.
>> 
>> I can see the justification of that for a desktop system which may be 
>> running a number of Python applications with conflicting dependencies. 
>> I'm less convinced that it is appropriate for an embedded platform 
>> more likely to be running a single application.
>> 
>>> However, for a clean venv you now need to install e.g. PyQt5, and 
>>> this
>>> fails, as outlined above. Is this a bug? Is this a flaw introduced by
>>> the Raspi packagers? Or is this a introduced by Debian packagers,
>>> which means it will soon become a broader problem?
>> 
>> It's not a bug, it's a consequence of those policy decisions.
>> 
>>> Can you say what packages need to be installed to make installation 
>>> of
>>> PyQt5 possible? Or is this a much deeper problem?
>> 
>> The build instructions are here...
>> 
>> https://www.riverbankcomputing.com/static/Docs/PyQt5/installation.html#building-and-installing-from-source 
>> ...but you also need platform-specific development packages installed.
>> 
>> This is not a PyQt-specific problem - it will affect any Python 
>> package that contains C/C++ extension modules and does not currently 
>> have Raspi wheels available on PyPI.
>> 
>> What's needed is somebody to step up and create Raspi PyQt wheels (I 
>> don't have the resources) which can be uploaded to PyPI so that "pip 
>> install PyQt5" will just work. I've made attempts over the years to 
>> engage with the Raspi community to address this but have never had a 
>> response.
>> 
>> Phil