[Development] Making Binary Incompatible Changes after Qt 6.0

[Volker Hilsheimer]

Hi,

Given the scale of Qt 6.0 it’s perhaps no surprise that in spite of careful reviews, we are seeing the first API issues popping up, fixing of which would require a breakage of binary compatibility. For example:

https://bugreports.qt.io/browse/QTBUG-87465

I’ve now created an EPIC type JIRA ticket through which we can keep track of such issues, so that we can understand the scale and impact of the overall problem.

https://bugreports.qt.io/browse/QTBUG-89157

The data collected there should then help us understand whether we should relax our binary compatibility guarantees for Qt 6.0. If you are aware of any, please link them to this ticket.

If we decide here to break BC before 6.1 because the available workarounds [1] are not applicable or not something we want to live with until Qt 7, then we might just as well go “all in” with such changes (as long as we maintain source compatibility).


Cheers,
Volker

[1] https://wiki.qt.io/Binary_Compatibility_Workarounds - that page is perhaps not as useful as it could be (but the KDE page linked is excellent)