Bug 483400

SUMMARY
I'm running a Docker container built from a Python:3.11-bullseye image, which uses Debian Bullseye packages. I tried to install KOpeningHours, but I got an error saying that ECMQmlModule wasn't found. This module comes from extra-cmake-modules (ECM), and the most recent version of ECM that Bullseye has is 5.78.0-3. Line 14 of CMakeLists.txt [1] in KOpeningHours seems to specify ECM version 5.44 as the minimum version, so I expected version 5.78.0-3 to work. 
However, ECMQmlModule was added in version 5.91.0 [2], so should the requested version of 5.44 be raised to 5.91?


STEPS TO REPRODUCE
1. Install a version earlier than 5.91.0 of extra-cmake-modules. I'll choose 5.78.0, which is the version found in Debian Bullseye. The following line installs ECM from source:
> git clone https://invent.kde.org/frameworks/extra-cmake-modules.git && cd extra-cmake-modules && git checkout v5.78.0 && cmake -S . && make install
2. Install KOpeningHours. In my case the location of the ECM library is in /usr/local/share/, so I added that to CMAKE_PREFIX_PATH. I'll use the most recent commit to KOpeningHours as of this bug report.
> CMAKE_PREFIX_PATH=/usr/local/share/ pip install git+https://invent.kde.org/libraries/kopeninghours.git@bf9fa422da84a9dbb55c0431955672a0bcda1ff4


OBSERVED RESULT
KOpeningHours is not installed. The following error can be seen in the output:

CMake Error at CMakeLists.txt:33 (include):
  include could not find requested file:
    ECMQmlModule


EXPECTED RESULT
KOpeningHours doesn't install, but the error instead mentions that the version of ECM is not compatible. Something like the following, which is shown when trying to install KOpeningHours using version of ECM lower than 5.44, like with 5.43.0:

CMake Error at CMakeLists.txt:14 (find_package):
     Could not find a configuration file for package "ECM" that is compatible
     with requested version "5.44".
     The following configuration files were considered but not accepted:
       /usr/local/share/ECM/cmake/ECMConfig.cmake, version: 5.43.0

An alternative could be an error mentioning which versions of ECM contain ECMQmlModule in order to successfully install KOpeningHours.


[1]: https://invent.kde.org/libraries/kopeninghours/-/blob/bf9fa422da84a9dbb55c0431955672a0bcda1ff4/CMakeLists.txt#L14
[2]: According to https://invent.kde.org/frameworks/extra-cmake-modules/-/commit/3813fd1bc97fa6bb2189cc9586f77be4c30478d6