When migrating a repository with git-lfs enabled, there are some additional steps. Git internal hooks don’t supply remote information, and the merging step will fail because git-lfs will try to smudge objects from lfs of the default branch instead. We can work around this limitation by turning off smudging and running git lfs pull on a specific remote manually.
monorepo$ git lfs install --skip-smudge --local
monorepo$ git merge other/main --allow-unrelated-histories
monorepo$ git lfs pull other
Related git-lfs issue number: 1759 (I can't post links)
This blog post is really helpful! Thanks Alex!