It’s recommended that you run the test suite with a custom environment set up, to make sure the test suite knows where the CRM instance is, and to allow you to customize the environment to support debugging if necessary. Copy tests/_envs/custom.dist.yml to tests/_envs/custom.yml and read through the file’s comments to configure your environment. custom.yml won’t be tracked by git, so it can be customized to work with your local environment without being reset or accidentally committed.
You can run codeception tests in a given environment like so: ./vendor/bin/codecept run acceptance --env custom
Note that the custom environment is only meant for use with the acceptance and install test suites. There’s also the travis-ci-hub.yml environment, which is meant for running the tests in Travis CI.