Change manjaro Stable to Testing or Unstable

#Change Repository Branch (temporary)

sudo pacman-mirrors -g -b testing

sudo pacman -Syyu


#Alternative: Amend the Repository Branch (permanent)

sudo [text editor] /etc/pacman-mirrors.conf

example

gksudo gedit /etc/pacman-mirrors.conf

## Branch Pacman should use (stable, testing, unstable) Branch=testing

save & exit

sudo pacman -Syyu