Using third-party repositories as instructed below could break your system now or when you upgrade later. Use with caution at your own risk!

1. Download packages containing the apt source file and public GPG key:

   wget https://kogiku.github.io/debian-repo/pool/main/k/kogiku-archive-keyring/kogiku-apt-source_2022.1-1_all.deb
   wget https://kogiku.github.io/debian-repo/pool/main/k/kogiku-archive-keyring/kogiku-archive-keyring_2022.1-1_all.deb

2. Then (as root) install the downloaded packages and update:

   apt install ./kogiku-*.deb
   apt update

Included packages:

apindex	amd64	from https://github.com/libthinkpad/apindex
bsnes-plus	amd64	from https://github.com/devinacker/bsnes-plus
cmdpack	amd64	from https://github.com/chungy/cmdpack
exhale	amd64	from https://gitlab.com/ecodis/exhale
gnome-icon-theme-s	all	from https://github.com/Kogiku/gnome-icon-theme-s
gogo	i386	from https://github.com/teragonaudio/gogo-no-coda
libvorbis-aotuv0	amd64, i386	from https://ao-yumi.github.io/aotuv_web
libvorbis-aotuv-dev	amd64, i386
libvorbisenc-aotuv2	amd64, i386
libvorbisfile-aotuv3	amd64, i386
motif-solaris-metacity-theme	all	from https://github.com/Kogiku/motif-solaris-metacity-theme
ncnn	amd64	from https://github.com/Tencent/ncnn
patchmatrix	amd64	from https://github.com/OpenMusicKontrollers/patchmatrix
python3-flac2all	all	from https://github.com/ZivaVatra/flac2all
python3-rivalcfg	all	from https://github.com/flozz/rivalcfg
realcugan-ncnn-vulkan	amd64	from https://github.com/nihui/realcugan-ncnn-vulkan
realsr-ncnn-vulkan	amd64	from https://github.com/nihui/realsr-ncnn-vulkan
sc-controller	amd64	from https://github.com/Ryochan7/sc-controller
sdlpal	amd64	from https://github.com/sdlpal/sdlpal
srmd-ncnn-vulkan	amd64	from https://github.com/nihui/srmd-ncnn-vulkan
ucon64	amd64	from https://ucon64.sourceforge.io
waifu2x-ncnn-vulkan	amd64	from https://github.com/nihui/waifu2x-ncnn-vulkan