I have been trying to learn CircleCi workflows by building simple jobs and I keep getting this error: /bin/bash: yarn: command not found.

So all the steps run but when it comes to the job is self it stops. So spin up environment, preparing env variables, checkout code, Restore Yarn Package Cache are green(successful).

My workflow below:

default-environment: &default-environment
  docker:
    - image: cimg/base:2020.01

step-restore-build-cache: &step-restore-build-cache
  restore_cache:
    name: Restore Yarn Package Cache
    keys:
      - yarn-packages-{{ checksum "yarn.lock" }}

step-save-build-cache: &step-save-build-cache
  save_cache:
    name: Save Yarn Package Cache
    key: yarn-packages-{{ checksum "yarn.lock" }}
    paths:
      - ~/.cache/yarn

step-run-cache: &step-run-cache
  run:
    name: Install Dependencies
    command: yarn install --immutable

version: 2.1
jobs:
  build:
    <<: *default-environment
    steps:
      - checkout
      - <<: *step-restore-build-cache
      - run:
          name: Build
          command: yarn run build
      - <<: *step-save-build-cache
  lint:
    <<: *default-environment
    steps:
      - checkout
      - <<: *step-restore-build-cache
      - run:
          name: Lint
          command: yarn run lint
  format:
    <<: *default-environment
    steps:
      - checkout
      - <<: *step-restore-build-cache
      - run:
          name: Format
          command: yarn run format
  type-check:
    <<: *default-environment
    steps:
      - checkout
      - <<: *step-restore-build-cache
      - run:
          name: Type-check
          command: yarn run type-check
workflows:
  version: 2
  build-and-lint:
    jobs:
      - build
      - lint
      - format
      - type-check

Not really sure how to fix this..

Thank you very much :)