In the past this has bitten me so many times. I don’t know if this will remain true and I might have stayed with Manjaro long ago if I knew this one thing. Don’t use the pamac GUI to apply big updates to Manjaro. If you use the pamac GUI to install an individual program make sure to check the Update tab first. Even though your intentions are to install an individual program you must realize that existing updates will also be applied and these updates can hose your system if applied with this GUI this way. At least that has been my experience. Instead install large updates on the command line first by typing sudo pacman -Syu. For example I wanted to install the ghex editor using this GUI and it reported a 400+MB of updates would be required. If history repeats itself, this would have surely hosed my system. Instead I first applied the big updates using the command line then I installed ghex with the GUI which required less than 2MB.