Too Long; Didn't Read
The story of deploying elixir applications in production is always a tough one. BEAM applications love to live in VM or bare metal without most abstractions. Nspawn is one of the components of Systemd-Nspawn that allows you to run containers (even docker containers) in your system. It's like chroot on steroids. The solution is to use a container with an OS identical to my production VM to deploy applications into production VMs. The only thing left is to trigger build inside of the container as part of the deploy process.