如何在没有`git push`的情况下配置远程上游

Question

Is it to possible to configure the remote upstream branch for a new local branch without doing a git push ?

I thought this is what --set-upstream-to option of git branch is for but I get the following error:

$ git branch --set-upstream-to remote2/foobar foobar

fatal: the requested upstream branch 'remote2/foobar' does not exist
hint: 
hint: If you are planning on basing your work on an upstream
hint: branch that already exists at the remote, you may need to
hint: run "git fetch" to retrieve it.
hint: 
hint: If you are planning to push out a new local branch that
hint: will track its remote counterpart, you may want to use
hint: "git push -u" to set the upstream config as you push.
hint: Disable this message with "git config advice.setUpstreamFailure false"

I'm aware of the config for the push command to do this automatically when pushing but I do not want to use that. What I'm trying to do is writing a script that makes sure main branch is pushed remote1 while all other branches are pushed remote2 . In particular I want it to (1) clone repo A from origin1 (2) add origin2 as a remote, (3) checkout a new local branch, (4) make sure git push on this branch goes to origin1 . I thought I could do something like this but I get the error above:

$ git clone git@github.com:username/repo1.git $1
$ pushd $1
$ git remote add origin2 git@github.com:username/repo2.git
$ git checkout -b $1
$ git branch --set-upstream-to origin2/$1
$ popd

Answer 1

If your intention is, in your script, to push to origin2 :

you can, especially in a script, explicitly type the full name of the remote reference, and additionally set the -u option to your git push command:

git push -u origin2 "$branch:refs/heads/$branch"

---

If your intention is, in your script, to just set the upstream branch and not push:

a "remote tracking branch" is just a setting (two actually) in your local .git/config file.

one hacky way to set a tracking branch that doesn't exist is to use git config :

git config "branch.$branch.remote" origin2
git config "branch.$branch.merge" "refs/heads/$branch"