Delete submodule
ref: https://gist.github.com/myusuf3/7f645819ded92bda6677?permalink_comment_id=3915500#gistcomment-3915500
# Remove the submodule entry from .git/config
git submodule deinit -f path/to/submodule
# Remove the submodule directory from the superproject's .git/modules directory
rm -rf .git/modules/path/to/submodule
# Remove the entry in .gitmodules and remove the submodule directory located at path/to/submodule
git rm -f path/to/submodule
Modify a commit (not last one)
ref: https://stackoverflow.com/questions/1186535/how-do-i-modify-a-specific-commit
git rebase --interactive bbc643cd~
# in vim, modify this commit to edit
git commit --all --amend --no-edit
git rebase --continue
LFS
Git LFS enables clone to fetch large files associated with a specific commit, rather than it's full history.
One needs to install git-lfs first:
apt-get install git-lfs
ref: https://zzz.buzz/zh/2016/04/19/the-guide-to-git-lfs (Chinese)