→Get the tools
pacman -S mingw-w64-i686-nsis
If you have version 3.04, The version in the mingw system has a bug that makes displaying of the font files during the AIO install messed up. I've created a patch, so we need to build our own.
Download https://gramps-project.org/wiki/index.php/File:Mingw-w64-nsis.zip [[:File:Mingw-w64-nsis.zip| (stored here)]] to a convenient location with your browser.