How do I modify the checkout step?

The checkout step

Checkout is a special step used to check out source code to the configured path. (The path defaults to the working directory.) It is more of a helper function designed to make checking out code easy for you.

The checkout step is a special convenience step in the form of a string and no additional attributes and it cannot be changed.

Modifying the checkout

If you need to change how the checkout step retrieves your code, you will need to perform raw git commands using a run step. In this, you will be able to customize the checkout process to suit your needs.

Example: 

 - run: git clone -b "$CIRCLE_BRANCH" "$CIRCLE_REPOSITORY_URL"

Please remember to remove the convenience checkout step if adding your own custom run step to process the checkout.