[Pkg-cmake-team] Bug#1087385: cmake 3.31.0-1 breaks Qt6Qml builds

[Brad King]

On Wed, Nov 13, 2024 at 8:24 AM Hefee wrote:
> 3.31.0 does  care about non existing directories in
> INTERFACE_INCLUDE_DIRECTORIES
> 3.30.5 do not care about non-existing directories.

I don't think that specific diagnostic has changed.
With this example:

```
cmake_minimum_required(VERSION 3.30)
project(DebianIssue1087385)
find_package(Qt6 REQUIRED COMPONENTS Qml)
add_executable(main main.cxx)
target_link_libraries(main PRIVATE Qt6::QmlPrivate)
```

both CMake 3.31.0 and 3.30.5 show:

```
CMake Error in CMakeLists.txt:
  Imported target "Qt6::QmlPrivate" includes non-existent path

    "/usr/include/x86_64-linux-gnu/qt6/QtQml/6.7.2"

  in its INTERFACE_INCLUDE_DIRECTORIES.
```

This was reported to Ubunu long before 3.31 came out:

* https://bugs.launchpad.net/ubuntu/+source/qt6-declarative/+bug/2054914

If 3.30.5 works and 3.31.0 fails, something else has changed
behavior that leads to this symptom.

-Brad