Github workflow errors out

Background

I have a small elixir project and I am trying to use GithubWorkflow to have a nice pipeline and automate some actions.

Problem

However I can’t even get it started as I get the following error:

 Setup elixir
1s
    AUCTION_HOUSE_TOKEN: ***
Run actions/setup-elixir@v1
  with:
    elixir-version: 1.10-otp-22
    otp-version: 22.1
    install-hex: true
    install-rebar: true
  env:
    COOKIE: ***
    TOKEN: ***
##[error]Cannot read property 'includes' of undefined

Code

I think my workflow might be incorrect, could someone help figure out what’s wrong?

name: build

on:
  push:
    branches: [ master ]
  pull_request:
    branches: [ master ]

env: 
  AUCTION_HOUSE_COOKIE: ${{ secrets.MARKET_MANAGER_WM_COOKIE }}
  AUCTION_HOUSE_TOKEN: ${{ secrets.MARKET_MANAGER_WM_XCSRFTOKEN }}

jobs:

  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Setup elixir
      uses: actions/setup-elixir@v1
      with:
        elixir-version: '1.10-otp-22' # Define the elixir version [required]
        otp-version: '22.1' # Define the OTP version [required]
    - name: Install Dependencies
      run: mix deps.get
    - name: Run Tests
      run: mix test
    - name: Run credo code analyser
      run: mix credo --strict
    - name: Run typechecks
      run: mix dialyzer
    - name: Build executable
      run: mix escript.build
      env: 
        MIX_ENV: prod