Is git clone --mirror dangerous?

Question

So I am going to migrate a bunch of repositories from bitbucket.org to a new on premise Bitbucket server instance.

What I can't decide on is whether to clone each repository as --bare or --mirror.

The scripted process seems pretty straight forward.

• Get the repositories from bitbucket.org and write them to a file for use and to keep as a log. (already done and works)

• Read the file, extract the repositories, repo slug(repo name) and clone them.(already working with --mirror)

• For each cloned repo, run:

  • git gc --auto to cleanup repos
  • Create repo from slug on new on premise server
  • git remote set-url origin ssh://on_prem_server:7999/PROJ/REPO
  • git push --all origin
  • git push --tags origin

So I am not actually mirroring the bitbucket.org repos but migrating them. My understanding is that git clone --mirror gives a true copy of original. While git clone --bare does not and needs at least a fetch afterwards. This is why I initially thought using --mirror was best.

But now I am worried that there could be some danger in using a mirror.

So my questions are.

• Are there any dangers using git clone --mirror I should be aware of?
• Should I even use --mirror or is --bare good enough?

Answer 1

--mirror just means to copy all refs "as-is" (instead of, for example, copying only branches and mapping them to remote tracking refs). Your use case is within its range of intended purposes.

(Just to clarify - --bare also maps refs directly rather than creating remote tracking refs form branches, but it doesn't copy all the refs like --mirror.)