cmake fails to generate QT6 build on Ubuntu 26.04

[Ferdi]

Since upgrading to Ubuntu 26.04 I can no longer build avidemux from git. This is because cmake fails to generate the QT6 part with the following error:

  Imported target "Qt6::GuiPrivate" includes non-existent path

    "/usr/include/x86_64-linux-gnu/qt6/QtGui/6.10.2"

[Ferdi]

When looking at the logfile, at first the qt6 include paths are correctly found.

However later on, another cmake script apparently adds the qt6 version number to the end of that path. This version number directory does not exist on my system causing the qt6 build to fail.

[eumagga0x2a]

This version number directory does not exist on my system

A big disclaimer: I don't have a working Ubuntu 26.04 on my PC yet (will probably create a VM as it doesn't seem to run on bare metal where gdm3 fails with NVIDIA driver installed – a combination where Fedora with RPM Fusion just works), but the list of files in qt6-base-private-dev

Code Select Expand

URL: https://packages.ubuntu.com/resolute/amd64/qt6-base-private-dev/filelist
includes the versioned directory. Will try to reproduce once I have got 26.04 running.