I have repo personal_stuff.git which I used to store a whole bunch of early-maybe-not-quite projects.
Every now and then one of them takes off, and I have to split a subfolder from personal_stuff/coolnewthing into its own coolnewthing.git repo.
To do this I use
git subtree split -P personal_stuff/coolnewthing -b coolnewthing
and then pull the new branch from another new git directory via:
git pull ../../../../personal_stuff coolnewthing
This works great, but I have all these commits in my history related to files that no longer exist.
How do I filter these out and keep only the commits relevant to the files that I still have?
You can make a new clone from the original repo and select a new root directory for this new local repo
git clone <url-to-personal_stuff.git> coolnewthing
cd coolnewthing
git filter-branch --subdirectory-filter coolnewthing
Note: the origin of this new local repo is still url-to-personal_stuff.git so you need to change the origin before you push
git remote set-url origin <url-to-coolnewthing.git>