World 10: Deep Git

git worktree

You will learn: how to work on two branches at once, in two folders, with one repo.

The problem

You are halfway through a big change. Then a bug report: fix main right now! Which way leaves your half-done work untouched?

Watch

~/diary $ git worktree add ../diary-fix -b fixPreparing worktree (new branch 'fix')HEAD is now at e0b2bc1 Add day 2~/diary $ git worktree list/home/you/diary     e0b2bc1 [main]/home/you/diary-fix e0b2bc1 [fix]

git worktree add makes a second working folder, on its own branch. Same repo, same history. Each folder is a .

Try it

Make a worktree at ../diary-fix on a new branch called fix.

Hint

Type git worktree add ../diary-fix -b fix.

Predict

You commit a fix inside diary-fix. Then you go back to diary. Can you see that commit there?

Watch

~/diary $ git worktree add ../diary-fix -b fixPreparing worktree (new branch 'fix')HEAD is now at e0b2bc1 Add day 2~/diary $ git worktree remove ../diary-fix~/diary $ git worktree list/home/you/diary e0b2bc1 [main]~/diary $ git branch  fix* main

Done? git worktree remove deletes the extra folder. The branch and its commits stay safe.

Check

Put the bug-fix trip in order.

First step at the top. Put these in order. Use the arrows, or drag.

cd ../diary
Fix the bug and commit
git worktree add ../diary-fix -b fix
git worktree remove ../diary-fix
cd ../diary-fix

You did it!

You can now work on two branches at once, in two folders.

Go deeper (optional)

A branch can be checked out in just one worktree at once. Git refuses a second one. git worktree remove refuses if the folder has changes; --force drops them. Deleted a worktree folder by hand? git worktree prune cleans up Git’s notes about it.