Branch 'main' set up to track remote branch 'main' from 'origin'. code example
Example 1: github set branch upstream
git push --set-upstream origin <remote-branch>
Example 2: git local branch track remote
git branch --set-upstream foo upstream/foo
Example 3: git link local branch to remote branch
git config remote.origin.fetch '+refs/heads/*:refs/remotes/origin/*'
Example 4: git local branch track remote
git branch --set-upstream-to=upstream/foo
git branch --set-upstream-to=upstream/foo foo