My working configuration for running codeception acceptance test with coverage and Yii 1 framework

acceptance.suite.yml

# Codeception Test Suite Configuration

# suite for acceptance tests.
# perform tests in browser using the Selenium-like tools.
# powered by Mink (http://mink.behat.org).
# (tip: that's what your customer will see).
# (tip: test your ajax and javascript by one of Mink drivers).

# RUN `build` COMMAND AFTER ADDING/REMOVING MODULES.

class_name: WebGuy
modules:
  enabled:
    - WebHelper
    - WebDriver
    - MailCatcherHelper
    - Db
  config:
    WebDriver:
      url: 'http://localhost'
      browser: firefox
    MailCatcherHelper:
      url: 'http://localhost'
      port: '1080'
    Db:
      dsn: 'mysql:host=localhost;dbname=mydb'
      user: 'vagrant'
      password: 'vagrant'
      dump: 'protected/data/mydb.sql'
      populate: true
      cleanup: false
env:
  jenkins:
    modules:
      config:
        WebDriver:
          url: 'http://192.168.2.205'
          browser: firefox
        MailCatcherHelper:
            url: 'http://192.168.2.205:1080/'
            port: '1080'
        Db:
            dsn: 'mysql:host=192.168.2.205;dbname=mydb'
            user: 'user'
            password: 'password'
            dump: 'protected/data/mydb.sql'
            populate: true
            cleanup: false
  vagrant:
    modules:
      config:
        WebDriver:
          url: 'http://localhost:8080'
          browser: firefox
        MailCatcherHelper:
            url: 'http://localhost:8088/'
            port: '1080'
        Db:
            dsn: 'mysql:host=localhost:3333;dbname=mydb'
            user: 'vagrant'
            password: 'vagrant'
            dump: 'protected/data/mydb.sql'
            populate: true
            cleanup: false

codeception.yml

paths:
    tests: tests
    log: tests/_log
    data: tests/_data
    helpers: tests/_helpers
settings:
    bootstrap: _bootstrap.php
    suite_class: \PHPUnit_Framework_TestSuite
    colors: true
    memory_limit: 1024M
    log: true
modules:
    config:
        Db:
            dsn: ''
            user: ''
            password: ''
            dump: tests/_data/dump.sql
coverage:
  enabled: true
  remote: true
  include:
      - protected/components/*
      - protected/config/*
      - protected/controllers/*
      - protected/messages/*
      - protected/models/*
      - protected/extensions/*
      - protected/modules/user/controllers/*
      - protected/modules/*
      - protected/views/*
      - themes/classic/*
  exclude:
      - vendor/*
      - protected/vendor/*
      - protected/tests/*
      - tests/*
      - protected/runtime/*
      - protected/extensions/EDataTables/*
      - protected/extensions/editable/*
      - protected/extensions/hoauth/*
      - protected/extensions/introjs/*
      - protected/extensions/jcrop/*
      - protected/extensions/mPrint/*
      - protected/extensions/phpexcelexporter/*
      - protected/extensions/TPPiwikAnalytics/*
      - protected/extensions/yii-mail/*

composer.json

{
    "require": {
        "codeception/codeception": "*"
    },
    "require-dev": {
        "codeception/codeception": "2.0.0-alpha"
    }
}

some configs

Make sure to have xdebug installed and enabled
Also give PHP scripts enough memory for execution on the webserver running the code coverage test (512M, rather more)