Merge two Git repositories

Merge two Git repositories.md

If you want to merge branch branchX from projectA into projectB:

cd path/to/projectA
git checkout branchX

cd path/to/projectB
git remote add projectA /path/to/projectA
git fetch projectA --tags
git merge --allow-unrelated-histories projectA/branchX
git remote remove projectA

Thanks to this answer!