https://devkitpro.org/wiki/Getting_Started
https://devkitpro.org/wiki/devkitPro_pacman
sudo apt-get install pkg-config wget
wget https://apt.devkitpro.org/install-devkitpro-pacman
chmod +x ./install-devkitpro-pacman
sudo ./install-devkitpro-pacman
nano /opt/devkitpro/pacman/etc/pacman.conf
Comment out the CheckSpace line
sudo dkp-pacman -S 3ds-dev
export DEVKITPRO=/opt/devkitpro
export DEVKITARM=/opt/devkitpro/devkitARM
export DEVKITPPC=/opt/devkitpro/devkitPPC
export PATH=$DEVKITPRO/tools/bin:$PATH
sudo apt-get install build-essential qtcreator git
cp -r /opt/devkitpro/examples ~