ffmpeg issues on nixos

trouble using ffmpeg: https://www.google.com/search?q=configure+XDG_RUNTIME_DIR+nixos&oq=configure+XDG_RUNTIME_DIR+nixos&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIICAEQABgWGB4yCAgCEAAYFhgeMggIAxAAGBYYHjIKCAQQABgKGBYYHjIICAUQABgWGB4yCAgGEAAYFhgeMgcIBxAAGO8FMgoICBAAGIAEGKIEMgcICRAAGO8F0gEIMTg3N2owajeoAgCwAgA&sourceid=chrome&ie=UTF-8

https://man7.org/linux/man-pages/man5/logind.conf.5.html

https://www.google.com/search?q=services.logind.settings.Login+tempdir&oq=services.logind.settings.Login+tempdir&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIHCAEQIRigATIHCAIQIRigATIHCAMQIRigATIHCAQQIRigATIHCAUQIRiPAjIHCAYQIRiPAjIHCAcQIRiPAtIBCDI4OTNqMGo3qAIAsAIA&sourceid=chrome&ie=UTF-8

https://www.google.com/search?q=nixos+%2Frun%2Fuser%2F1000+out+of+space&oq=nixos+%2Frun%2Fuser%2F1000+out+of+space&gs_lcrp=EgZjaHJvbWUyCQgAEEUYORigATIHCAEQIRiPAjIHCAIQIRiPAtIBCDM2NzBqMGo3qAIAsAIA&sourceid=chrome&ie=UTF-8

I got sounds here https://www.tubebuddy.com/blog/royalty-free-music-sites-for-youtube/

chatgpt thread of deailing wit hnixos: https://chatgpt.com/c/6952be99-4208-8329-9764-855bcce507b9

After I migrated to proxmox I have attached hard drives so here is how i brought over videos:

# Will create the sub-directory automatically
rsync -av root@192.168.4.100:/mnt/Old_School_HDD/Volleyball/2025-12-08 /home/lane/Videos/Volleyball

 sudo chmod -R 777 ~/Videos/Volleyball/

nix-shell -p ffmpeg-full

probably should reference this: Working with volleyball videos