mkspecs files currently get installed to /usr/mkspecs which is incorrect I added this attached patch to install it to the correct directory Reproducible: Always
Created attachment 89731 [details] install to correct dir patch from kubuntu package to install to correct dir we also have to set -DQCA_SUFFIX="qt5" because it is not binary compatible. The correct fix is to change the soversion which is at https://git.reviewboard.kde.org/r/121168/
Created attachment 89732 [details] Error when installing
I tried to compile and install with your patch in own home directory. I got error. When using CMAKE_INSTALL_PREFIX all files MUST be under CMAKE_INSTALL_PREFIX. The patch brokes this. So patch is not correct. Use QCA_FEATURE_INSTALL_DIR to set correct feature dir or not use CMAKE_INSTALL_PREFIX