Bug 1902618 - python-pyside2 fails to build with Python 3.10: Py_REFCNT= needs to be replaced with Py_SET_REFCNT
Summary: python-pyside2 fails to build with Python 3.10: Py_REFCNT= needs to be replac...
Alias: None
Product: Fedora
Classification: Fedora
Component: python-pyside2
Version: rawhide
Hardware: Unspecified
OS: Unspecified
Target Milestone: ---
Assignee: Richard Shaw
QA Contact: Fedora Extras Quality Assurance
Depends On:
Blocks: PYTHON3.10
TreeView+ depends on / blocked
Reported: 2020-11-30 08:02 UTC by Tomáš Hrnčiar
Modified: 2021-02-09 16:23 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed:
Type: Bug

Attachments (Terms of Use)

Description Tomáš Hrnčiar 2020-11-30 08:02:18 UTC
python-pyside2 fails to build with Python 3.10.0a2.

/sources/shiboken2/libshiboken/sbkstring.cpp:250:23: error: expression is not assignable
        Py_REFCNT(ob) = 1;
        ~~~~~~~~~~~~~ ^
1 error generated.


bpo-39573: Convert Py_REFCNT() and Py_SIZE() macros to static inline functions. They cannot be used as l-value anymore: use Py_SET_REFCNT() and Py_SET_SIZE() to set an object reference count and size. This change is backward incompatible on purpose, to prepare the C API for an opaque PyObject structure.

For the build logs, see:

For all our attempts to build python-pyside2 with Python 3.10, see:

Testing and mass rebuild of packages is happening in copr. You can follow these instructions to test locally in mock if your package builds with Python 3.10:

Let us know here if you have any questions.

Python 3.10 will be included in Fedora 35. To make that update smoother, we're building Fedora packages with early pre-releases of Python 3.10.
A build failure prevents us from testing all dependent packages (transitive [Build]Requires), so if this package is required a lot, it's important for us to get it fixed soon.
We'd appreciate help from the people who know this package best, but if you don't want to work on this now, let us know so we can try to work around it on our side.

Comment 1 Miro Hrončok 2020-11-30 10:10:15 UTC
Victor, please take a look.

Comment 2 Victor Stinner 2020-11-30 10:47:46 UTC
I'm working on a fix: https://src.fedoraproject.org/rpms/python-pyside2/pull-request/7

Comment 3 Victor Stinner 2020-11-30 11:20:52 UTC
I reported the issue to Qt upstream (PySide project): https://bugreports.qt.io/browse/PYSIDE-1436

Comment 4 Richard Shaw 2020-12-05 13:04:17 UTC
Upstream is having a very active discussion on the fix so I would rather wait for them than apply the patch which just makes it "build". 

Hopefully they'll provide a patch (or something that I can make a patch from) and we won't have to wait until the next patch release.

Comment 5 Ben Cotton 2021-02-09 15:29:05 UTC
This bug appears to have been reported against 'rawhide' during the Fedora 34 development cycle.
Changing version to 34.

Note You need to log in before you can comment on or make changes to this bug.