nil can't be coerced into Fixnum error while running tests on circle ci in minitest/ci_plugin.rb:113

[Minitest::CI] Generating test report in JUnit XML format...
/home/circleci/circleci-demo-ruby-rails/vendor/bundle/ruby/2.2.0/gems/minitest-ci-3.3.0/lib/minitest/ci_plugin.rb:113:in `+': nil can't be coerced into Fixnum (TypeError)

This is the error we are seeing We are upgrading our app from rails 3 to rails 4.2 with new ruby and also from old config to circleci 2.0

Following is the circleci config, if it helps

version: 2
jobs:
  build:
    docker:
      - image: circleci/ruby:2.2.8-browsers
      - image: mysql:5.7.20
        environment:
          - MYSQL_ALLOW_EMPTY_PASSWORD=yes
          - MYSQL_ROOT_HOST=%
      - image: redis:3.2.4
      - image: docker.elastic.co/elasticsearch/elasticsearch:5.6.2
        environment:
          - discovery.type=single-node
          - http.host=0.0.0.0
          - transport.host=127.0.0.1
          - xpack.security.enabled=false
          - ES_JAVA_OPTS=-Xms750m -Xmx750m
    parallelism: 1
    working_directory: ~/circleci-demo-ruby-rails
    steps:
      - checkout
      - run:
          name: git
          command: git --version
      - run:
          name: firefox
          command: firefox -version
      - run:
          name: ruby version
          command: ruby --version
      - run:
          name: install mysql client
          command: sudo apt-get update && sudo apt-get install -y mysql-client
      - run: cp config/database.ci.yml config/database.yml
      # Restore bundle cache
      - restore_cache:
          key: circlev2-{{ checksum "Gemfile.lock" }}
      - run: bundle check --path=vendor/bundle || bundle install --path=vendor/bundle --jobs=4 --retry=3
      # Store bundle cache
      - save_cache:
          key: circlev2-{{ checksum "Gemfile.lock" }}
          paths:
            - vendor/bundle
      - run: mkdir ~/reports
      - run: RAILS_ENV=test bundle exec rake db:create
      - run: RAILS_ENV=test bundle exec rake db:structure:load
      - run:
          name: rails tests
          command: "RAILS_ENV=test bundle exec rake test TESTOPTS='--ci-dir=./reports'"
          no_output_timeout: 1800
      - store_test_results:
path: ~/reports

CircleCI-Public / minitest-ci

nil can't be coerced into Fixnum error while running tests on circle ci in minitest/ci_plugin.rb:113 #22