"What ends up happening is that the split off folder will live in two
repositories: the existing repo and the one setup as a subtree. You
need to explicitly commit changes to subtree. This is obviously a
mixed blessing. If you have a repository with a few occasional
committers, they can pull the original repository and push as if the
subtree didn’t exist. Then some one on the core team could
occasionally push to the subtree."
This is great and all, but is there a way to remind people committing that they are using a sub-tree repository, and also need to commit their changes individually in the sub-tree repo?
I'm thinking for instance:
-mswitch for commit messages.
Maybe you could use a CI server to keep the subtree repository up-to-date. People in the main project could just keep committing to the main repository without caring too much about the subtree and an automatically triggered CI job would perform the subtree push.