CircleCi tries to install composer and fails, despite my circle.yml is completely different

Feedback & Bug Reports
1

I posted this issue also here /bin/bash: composer: command not found.

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:

CircleCI

I don’t know why CIrcleCI started to ignore my circle.yml file completely and treats app like PHP. When I go to the build page and configuration tab there is something like this:

# PHP CircleCI 2.0 configuration file
#
# Check https://circleci.com/docs/2.0/language-php/ for more details
#
version: 2
jobs:
  build:
    docker:
      # specify the version you desire here
      - image: circleci/php:7.1.5-browsers

      # Specify service dependencies here if necessary
      # CircleCI maintains a library of pre-built images
      # documented at https://circleci.com/docs/2.0/circleci-images/
      # - image: circleci/mysql:9.4

    working_directory: ~/repo

    steps:
      - checkout

      # Download and cache dependencies
      - restore_cache:
          keys:
          - v1-dependencies-{{ checksum "composer.json" }}
          # fallback to using the latest cache if no exact match is found
          - v1-dependencies-

      - run: composer install -n --prefer-dist

      - save_cache:
          paths:
            - ./vendor
          key: v1-dependencies-{{ checksum "composer.json" }}

      # run tests!
      - run: phpunit

But I don’t have anything like that in the repo (though I do have composer.json file).

Why CircleCI started ignoring my config?

Latest build that succeeded in configuration tab has correct config…