version: 2
jobs:
  build:
    docker:
      - image: debian:stretch

    steps:
      - checkout

      - run:
          name: Install required tools
          command: 'apt-get update && apt-get install -y gcc g++ git cmake'
      - run:
          name: Show versions
          command: 'g++ --version ; uname -a; cmake --version'
      - run:
          name: Run CMake
          command: 'mkdir build ; cd build ; cmake ..'
      - run:
          name: Compile
          command: 'cmake --build build'
      - run:
          name: Execute test suite
          command: 'cd build ; ctest --output-on-failure -j 2'

version: 2
jobs:
  build_stable:
    docker:
      - image: debian:stretch

    steps:
      - checkout

      - run:
          name: Install required tools
          command: 'apt-get update && apt-get install -y gcc g++ git cmake'
      - run:
          name: Show versions
          command: 'g++ --version ; uname -a; cmake --version'
      - run:
          name: Run CMake
          command: 'mkdir build ; cd build ; cmake ..'
      - run:
          name: Compile
          command: 'cmake --build build'
      - run:
          name: Execute test suite
          command: 'cd build ; ctest --output-on-failure -j 2'

Rename `build` job to `build_stable` to be more descriptive.
Rename `build` job to `build_stable` to be more descriptive.
