Although not required, we recommend using Nix flake as part of ea's development process: to replicate the exact development environment as the maintainers, run nix shell, or adding use flake in an direnv .envrc file.
If you update Cargo.toml in any way, you will have to update flake.nix, this is enforced by checks in continuous integration.
If you don't use Nix, see buildInputs in flake.nix for the tools necassary to the development.