Here's a common flow where I find stacked PRs are useful:
- I want to build feature X
- Ah, but it would work better if I refactored the module first
- I refactor then build feature X
- There's then some additional (and optional) cleanup work
As a reviewer I wouldn't want to see all this in a single PR, and the changes depend on each other so I can't open multiple independent PRs. Manual rebasing is fine but navigating the GitHub UI is then annoying, I have to mentally keep track of where I am in the stack.
I certainly don't want to see that in a one commit. A PR has one more more commits, though.
The commits in a PR are already a stack of patches, and so PRs are already "stacked" as they are.
If feature X depends on the refactoring (cannot be rebased on the un-refactored upstream), it's part of the change; you can't just merge the feature and not the refactoring.
If the two are separable that way then, sure, it makes sense to ask for them to be separate PRs.
I do that too. I do introduce changes in separate PRs. They could be related to the same problem and referenced accordingly.
and the changes depend on each other so I can't open multiple independent PRs
Why? Is it a technical restriction? Tightly coupled architecture is not the best solution anyway.
Those could just be individual commits on a branch. Why does it need to be a stacked PR? That concept really only exists within the interfaces of these kinds of tools.