In Magento 1, we can directly add the breadcrumb in checkout page using XML.

But in Magento 2 there are some changes to add the breadcrumb

1. Copy the checkout_cart_index.xml file in your theme. And then write code in body tag

<referenceBlock name="breadcrumbs">
<action method="addCrumb">
<argument name="crumbName" xsi:type="string">Home</argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string">Home</item>
<item name="label" xsi:type="string">Home</item>
<item name="link" xsi:type="string">/</item>
</argument>
</action>
<action method="addCrumb">
<argument name="crumbName" xsi:type="string">Shopping Cart</argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string">Shopping Cart</item>
<item name="label" xsi:type="string">Shopping Cart</item>
<item name="link" xsi:type="string">/checkout/cart</item>
</argument>
</action>
</referenceBlock>

Now Refresh the page and check