export RUBY_VERSION=2.7.0
export GITHUB_INSTALL_SCRIPTS=https://raw.githubusercontent.com/danbooru/danbooru/master/script/install
export VIPS_VERSION=8.7.0
Those are the packages you'll have to install. I'd recommend an installation of yay as some of these require the AUR. And I also recommend that you install each package separately.
yay -S zlib glib2
yay -S base-devel automake openssl openssl-1.0 libxml2 libxslt ncurses readline6 readline7 readline flex bison ragel memcached libmemcached git curl libcurl-openssl-1.0 imagemagick sendmail nginx openssh redis coreutils ffmpeg mkvtoolnix npm
yay -S postgresql postgresql-libs
yay -S lcms2 libjpeg-turbo expat giflib libpng libexif
yay -S gcc
sudo npm install -g yarn
sudo npm install -g nodejs
Now configure and build libvips. You can install the one from arch's repositories, but building it is better most of the time.
cd /tmp
wget -q https://github.com/libvips/libvips/releases/download/v$VIPS_VERSION/vips-$VIPS_VERSION.tar.gz
tar xzf vips-$VIPS_VERSION.tar.gz
cd vips-$VIPS_VERSION
./configure --prefix=/usr
make
make install
ldconfig
useradd -m danbooru
chsh -s /bin/bash danbooru
usermod -G danbooru,sudo danbooru