Migrate one repo-a into another repo-b
git clone </path/to/repo-b>
git checkout -b branch-to-merge-repo-a
git subtree add -P aws ssh://git@git.fei.com:7999/in/aws.git <revision>
git push
Then create pull request and merge the new branch into master
Import file/folder history from one repo-a to repo-b
cd repository
git log --pretty=email --patch-with-stat --reverse --full-index --binary -- cloudformation/opensearch > ~/tmp/opensearch.patch
cd ../another_repository
git am --committer-date-is-author-date < ~/tmp/opensearch.patch
git log --pretty=email --patch-with-stat --full-index --binary --reverse -- client > patch
