Development Environment

Most Lighthouse developers work on Linux or MacOS, however Windows should still be suitable.

First, follow the Installation Guide to install Lighthouse. This will install Lighthouse to your PATH, which is not particularly useful for development but still a good way to ensure you have the base dependencies.

The only additional requirement for developers is ganache-cli. This is used to simulate the Eth1 chain during tests. You'll get failures during tests if you don't have ganache-cli available on your PATH.


As with most other Rust projects, Lighthouse uses cargo test for unit and integration tests. For example, to test the ssz crate run:

cd consensus/ssz
cargo test

We also wrap some of these commands and expose them via the Makefile in the project root for the benefit of CI/CD. We list some of these commands below so you can run them locally and avoid CI failures:

  • $ make cargo-fmt: (fast) runs a Rust code linter.
  • $ make test: (medium) runs unit tests across the whole project.
  • $ make test-ef: (medium) runs the Ethereum Foundation test vectors.
  • $ make test-full: (slow) runs the full test suite (including all previous commands). This is approximately everything that is required to pass CI.

The lighthouse test suite is quite extensive, running the whole suite may take 30+ minutes.

Ethereum 2.0 Spec Tests

The ethereum/eth2.0-spec-tests repository contains a large set of tests that verify Lighthouse behaviour against the Ethereum Foundation specifications.

These tests are quite large (100's of MB) so they're only downloaded if you run $ make test-ef (or anything that run it). You may want to avoid downloading these tests if you're on a slow or metered Internet connection. CI will require them to pass, though.