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.
Regardless of whether the former solves it, I was going to suggest you could use compose or whatever in your 'human' tree, and then tell the AI to use equivalent docker commands without using compose, so it gets anonymous/its own named containers, but you keep the convenience.
When opening the posted link, my first thought was "imagine if the stacked PRs site had the same amount of effort put into it as the Github Copilot App site". They clearly have other preview features on this site already, so maybe I'm just confused on why stacked PRs got some b-grade announcement site. The obvious answer is "copilot", but I'm still curious.
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).
Last month I used Copilot heavily, much much more than I usually do, but did not manage to use more than 58%.
Forced me to switch to OpenCode Go (not Zen), which isn't quite as nice as Copilot Chat deeply integrated into VSCode / Intelli but the models (DeepSeek v4 Pro, GLM 5.1, & Qwen 3.7 Max) are able replacements for Claude Sonnet 4.x / GPT 5.x while being way cheaper (especially DeepSeek).
I swear I did few tests and it's rare you need more than medium on mundane job work.
Edit: This short talk – https://maggieappleton.com/zero-alignment
Particularly the left sidebar and conversation view look near identically structured.
the copilot app looks more like just a straight clone of the codex UI (and the new antigravity UI, which is also a straight clone of the codex UI)
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.
[1]: https://github.blog/news-insights/company-news/an-update-on-...
But!
The reason these tools exist is not because of non-professional developers, but quite the opposite.
A lot more professionals are now working on more projects simultaneously- something that was not practical just a year ago.
Though, while this is nice, considering that all of the action is happening on the same device, I am worried this is going to increase supply chain risks. Before, a developer would work on clearly designated projects for practical reasons. Now, the same developer can work across many projects that are quite different - for example, the marketing site and the backend - and because of an obscure and unimportant component on the marketing site, there can be an impact on backend systems.
I wrote more about this here: https://chatbotkit.com/reflections/everyone-is-a-vip-now
What I've done on my end is created a project where I have a remote Linux workstation. I can create multiple worktrees for each repo in that workstation, and then my agent can push PRs to GitHub and use the actions infrastructure to see if the integration tests that it writes for itself are successful without needing to run those integration tests on the local environment. It's expensive in terms of runner hours, but the automaticity of it is incredible.
Go here and you’ll be redirected with a query string including a customer parameter. That looks like trouble.
Now they want to end that collaboration, and turn it into automation. Many C-suite executives right now are smiling bigly. Meanwhile, we're leading the exodus. Turns out, we still want the easiest and prettiest way to participate in the collaborative development of software, and GitHub ain't it!
Other than fewer features.
These desktop agentic coding tools are a large UX step up from the CLIs, but I still think the future is going to be remote development as the coding agents start running for hours at a time. Building a desktop app seems short-sighted as it would just lock them out of the remote option completely.
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)
I predict next “Windows Copilot App” (not to be confused with any of the others), Microsoft’s AI that controls your computer (like OpenAI Operator and Claude Computer)
Plus the whole naming confused people
I still talk to co-workers who think claude code == agents and copilot is just VS autocomplete
And after they will accuse the growth and all to be responsible for their stability issues...