cmake/Mosquitto.cmake finds it through pkg-config; with FRAMEASSISTANT_SHIP_MOSQUITTO=ON (all package presets) it installs lib/libmosquitto.so.1 and Debian's copyright file and excludes the library from the Qt bundler (D35). The build containers get libmosquitto-dev, the test container the mosquitto broker. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>