This repository provides a nix package of neovim nightly. If you want to try bleeding edge features like floating window support and you are using Nix/NixOS you have come to the right place ;-)
$ nix-env -i -f https://github.com/gilligan/nix-neovim-nightly/tarball/master
NOTE: neovim is installed as nvim-nightly since you might want to install it side by side with
a stable neovim version.
You can also make use of cachix if you want to avoid building anything
$ cachix use neovim-nightly
This build uses the this nixpkgs fork mentioned in this nixpkgs issue since building recent neovim versions from master is currently broken on nixpkgs.