[Development] PSA: CMake 3.26+ recommended for configure -no-prefix / -developer-build builds

[Alexandru Croitor]

Hi,

For Qt 6.10, changes were implemented to split QtModulePrivate targets into separate CMake packages, to ease Linux distribution packaging,
so they have better file boundaries for their qtfoo vs qtfoo-devel packages.

See https://bugreports.qt.io/browse/QTBUG-87776 for details

Unfortunately this was not trivial to do, and various edge cases came up along the way.

If you are a Qt developer, and configured a -developer-build on macOS with CMake < 3.26, you might have hit an issue where user projects couldn't find QtCore again.

This was worked around with https://codereview.qt-project.org/c/qt/qtbase/+/629669 
but it means private modules will always be looked up in such a scenario, and thus is different to what the CI does.


To minimise the difference of -no-prefix / -developer-builds to the CI ones, we recommend using at least CMake 3.26 locally.

You will get a warning when using a lower version. The build should still work, but it will not match what the CI does, so be aware.

Regards,
Alexandru.