It isn't, but it is limited to a few source control solutions. If you use something other than Git, Bazaar, SVN, Mercurial, or Fossil, then you're not going to be able to publish Go modules.
Also, Go modules are dependent on DNS, so any domain name change for your repo will have to result in code (import path) changes.
Also, Go modules are dependent on DNS, so any domain name change for your repo will have to result in code (import path) changes.