There are two Git repositories, the old and the new, can they be merged?

Question

For example:
Warehouse A: From version 1.0 -> 1.1 -> 2.0
Warehouse B: From version 2.0 -> 2.1 -> 2.2

Can warehouses A and B be merged to form a complete single warehouse 1.0 -> 1.1 -> 2.0 -> 2.1 -> 2.2?

Answer 1

Create a new remote on B, pointing to A. Then rebase A

git remote add upstream A
git fetch upstream
git rebase upstream

Answer 2

The warehouses are independent and there is no merging mechanism. There can be branches under the same warehouse, and branches can be merged.

Answer 3

It can be done by cramming all these commits into one repo

But you can’t change the existing commit. You can’t connect 1.1 in front of 2.0. You can only rebuild 2.0 / 2.1 with the same content after 1.1