collective.cart.core is yet another cart for Plone.
You may list collective.cart.core to buildout.cfg or setup.py in your own package.
Use zc.buildout and the plone.recipe.zope2instance recipe by adding collective.cart.core to the list of egg:
[buildout] ... eggs = ... collective.cart.core
You may also list to install_requires to setup.py within your package.