The newest version of macOS 10.14 has now been released and this time there are two major changes that affect Qt applications: Core Animation (CA) layer backing is enabled for all native views, and dark mode has been introduced. We’ve been testing on the betas since this summer, those who follow Qt development closely might have seen the commits.
The Qt release target for the fixes is the 5.12 branch, which has a couple of implications for Qt users:
We encourage upgrading to Qt 5.12 to get fixes for macOS 10.14
The maximum supported Xcode version for Qt 5.11 and lower is Xcode 9 (SDK 10.13)
The latter point may require further explanation. New features such as Dark Mode, or behavior changes such as CA layer backing are gated on the SDK version used to link the application. This provides a compatibility mode for existing binaries and for code bases that have not yet been updated.
This workaround of using an older Xcode and SDK version also applies when using Qt 5.12, if you encounter a bug related to dark mode or layer backing that we have not fixed in Qt.