Is there a switch available to disable MQTT when building GSE ?
No there wont be a switch to disable it. Btw. you are running an unreleased in development version from the main branches. This might break every time.
Sorry, for wasting your time, a typo in the version string used in the build script pointed to 21.4.5 for gvm-libs and not to 21.4.4.
Thanks for your help.