This might be a QT6 missing dependency during the package build? I did this:
1. sudo apt build-dep calamares 2. Downloaded the 3.3.12 source directly from GitHub - calamares/calamares: Distribution-independent installer framework <https://github.com/calamares/calamares> 3. During configuring the build with a cmake .. (in a dedicated build directory), it states: -- Skipped modules: -- Skipped fsresizer (missing suitable KPMcore). -- Skipped partition (missing suitable KPMcore). Going up further in the cmake output: CMake Warning at CMakeModules/KPMcoreHelper.cmake:21 (find_package): Found package configuration file: /usr/lib/x86_64-linux-gnu/cmake/KPMcore/KPMcoreConfig.cmake but it set KPMcore_FOUND to FALSE so package "KPMcore" is considered to be NOT FOUND. Reason given by package: KPMcore could not be found because dependency Qt6 could not be found.

