I have a golang project which imports some third-party packages. Today, i want to upgrade it but one of the packages's git repo has been removed by author for some reason. I know Python has "pypi" to manage all the third-party packages. Is there any platform like that can keep a copy of these packages or some other ways to avoid packages being removed?
The simplest way to do this would be for you to simply fork the git repository, and use this version instead of the "live" one. This way you could test for compatibility before upgrades, etc, and ensure that your dependency is available for as long as you are working with it.
There may be platforms that provide this kind of service, but as a whole, you can't rely on them either. And the majority of them is more focused on versionning, keeping archives is only a (kind of) side-effect.