### Changed
- Use nix from nixpkgs rather than from PATH. This is needed when the nix in
PATH is nixUnstable-3.0pre20201020_e0ca98c or later because nix commit
### Changed
- Use nix from nixpkgs rather than from PATH. This is needed when the nix in
PATH is nixUnstable-3.0pre20201020_e0ca98c or later because nix commit