You need a working Docker and Rust with MUSL environment to run the CI locally. If you work on macOS, Homebrew's musl-cross package should work.
Once you open a pull request for RustyBGP, the CI will be executed on Github Actions. It's better to run the CI locally for your change in the following way before opening a pull request.
$ ./tests/integration/functional/local-ci.sh build
$ ./tests/integration/functional/local-ci.sh start
=== RUN TestEbgp
rusty image name rustybgp-ci
gobgp image name tomo/gobgp
--- PASS: TestEbgp (17.73s)
PASS
ok github.com/osrg/rustybgp/tests/integration/functional/pkg 17.758s
=== RUN TestIbgp
rusty image name rustybgp-ci
gobgp image name tomo/gobgp
--- PASS: TestIbgp (32.15s)
PASS
ok github.com/osrg/rustybgp/tests/integration/functional/pkg 32.179s