A repository folder can only be on one branch at a time.

A worktree is basically equivalent to a cp -R + git branch, which allows this new workflow to occur.

I loved this particular historical insight as to why `git worktree` was added in 2015:

Before worktrees, kernel devs faced a major inconvenience when switching contexts, e.g., stopping feature work to fix an urgent bug on a release branch.

Running git stash and switching branches alters timestamps on thousands of files.

This forces `make` to perform a full re-compile, which can take up to an hour on large kernels.

I swear I did few tests and it's rare you need more than medium on mundane job work.

Particularly the left sidebar and conversation view look near identically structured.

This app is just another "let me talk to product, copy their convo, go off and build this in isolation with an agent" which I think is directionally wrong.

The "rooms" or "streams" should be multi-player instead of product looking at it at the end saying "no, go fix that" and dev copies text from one source and pastes into another.

Target market for copilot includes people with actual purchasing power and also many new users where this is an actual make or break feature. So this is worth the investment into design while stacked PRs is questionable. I actually question why they bothered with anything more than a blog post at all for stacked PRs (looking at the post it doesn't seem like too too much more than a blog post though).

There's support in VS Code and Jetbrains IDEs. You can access your agent sessions on the web.

(I work at GitHub, but not on Copilot)

Plus the whole naming confused people

I still talk to co-workers who think claude code == agents and copilot is just VS autocomplete