alt Hacker NewsThe fact that nearly all of our source code is not only hosted on proprietary platforms that can (and do) delete it any time they like, but is ALSO integrated with many of our build systems so that it’s not trivially relocatable blows my mind every time I think about it.
If you want to be serious about this, use a self-hosted CI/CD server such as TeamCity, and then mirror all dependencies on a local git server (Go supports GOPROXY variable, but you can also probably fiddle with local DNS and self-signed certs, so that any mention of github.com forwarded you to the local server). This way, it's more controllable: if github.com is down or some repo is deleted, the CI/CD server won't even notice it.