Which is a poor solution since it involves checking all your dependencies into source control. There's no reason why you shouldn't be able to have a file that lists all your dependencies and versions and lets you pull them down on-demand.
If you can't build and deploy your own system without a piece of code, you should not be relying on the goodwill of any third party to keep it available for you with no SLA. A good build system is a deterministic function of its input (a commit from your repo) and can run offline.
