[PyQt] PyQt5/QtCore.so: undefined symbol: PySlice_AdjustIndices

[Phil Thompson]

On 9 Aug 2018, at 9:19 am, Florian Bruhin <me at the-compiler.org> wrote:
> 
> Hey,
> 
> On Thu, Aug 09, 2018 at 08:03:36AM +0000, Blanc Nicolas wrote:
>> I encountered the following error when using PyQt5 with Python 3.5 on Ubuntu 16.04 (4.15.0-29-generic x86_64 GNU/Linux)
>> My PyQt5 version is : 5.11.2
>> And PyQt5_sip : 4.19.12
>> Both installed using pip3.
>> 
>> Here is the error :
>> 
>> 
>> $ python3
>> Python 3.5.2 (default, Nov 23 2017, 16:37:01)
>> [GCC 5.4.0 20160609] on linux
>> Type "help", "copyright", "credits" or "license" for more information.
>>>>> import PyQt5
>>>>> from PyQt5 import QtCore
>> Traceback (most recent call last):
>>  File "<stdin>", line 1, in <module>
>> ImportError: /usr/local/lib/python3.5/dist-packages/PyQt5/QtCore.so: undefined symbol: PySlice_AdjustIndices
> 
> It's a Python bug which was fixed in 3.5.4. Unfortunately, Ubuntu
> prefers keeping older buggy versions ;-)

To be honest it's a PyQt bug that wasn't picked up because it only affected earlier versions of Python.

The lesson is to only test with the x.y.0 versions.

Phil