How to sync up private forks of a public repository

Regular commits

Github does not offer automation, like Pull Requests, across private/public forks. One needs to push changes manually:

# Change directory to your forked repo
git fetch upstream
git checkout main
git merge upstream/main

Manual synchronization of the Git LFS files is required after each PR merged in the upstream repo:

git remote add upstream https://github.com/ease-lab/vhive
git lfs fetch --all upstream
git lfs push --all origin

This command sequence does not create commits in the forked repo.