Since today (15.02.2017) my CircleCI builds started to fail. Yesterday (14.02.2017) it was ok.
Here is my circle.yml (which I have not changed since long time):
    general:
  build_dir: frontend
  branches:
    only:
      - frontend/develop
machine:
  environment:
    PATH: "${PATH}:${HOME}/${CIRCLE_PROJECT_REPONAME}/node_modules/.bin"
  node:
    version: 8.0.0
dependencies:
  override:
    - yarn
  cache_directories:
    - ~/.cache/yarn
compile:
  override:
    - echo "build on heroku"
test:
  override:
    - yarn test
deployment:
  dev:
    branch: frontend/develop
    commands:
      - |
        cat >~/.netrc <<EOF
        machine api.heroku.com
          login $HEROKU_EMAIL
          password $HEROKU_TOKEN
        machine git.heroku.com
          login $HEROKU_EMAIL
          password $HEROKU_TOKEN
        EOF
      - chmod 600 ~/.netrc # Heroku cli complains about permissions without this
      - cd .. && git push git@heroku.com:my-project.git `git subtree split --prefix frontend`:master --force
I am getting following error during the build.

What’s going on? I am NOT using composer, it seems that builds fail at startup of build process…