I personally find multi-repo thinking leads to better architecture. Cross project change history seems nice but if the projects are that coupled in the first place, why are they difference solutions to begin with? If you're building decoupled code you shouldn't need cross project changes.
That said, I understand the worth of getting things done at the expense of rigor so I chalk this topic of discussion up to personal taste. It's akin to the dynamic vs static typing debate.
> If you're building decoupled code you shouldn't need cross project changes.
That's the theory, but in practice designing robust, future proof APIs has proven to be really hard in a lot of cases. You're then left with the option of supporting old APIs forever or migrating dependent code to new APIs, both of which are difficult in their own ways.
That has nothing to do with requiring an atomic cross project change. If your depended library needs to be updated, update as needed.
Upgrading other projects to support the new dependency version can come in a different commit. You only run into trouble when you've set up your projects to always use the latest version of their dependencies. That's a recipe for disaster.
That said, I understand the worth of getting things done at the expense of rigor so I chalk this topic of discussion up to personal taste. It's akin to the dynamic vs static typing debate.