git-partial-merge-repos.md

I don't care about history

git remote add secret_prefix-tools ssh://[email protected]:1234/secret_prefix-tools
git fetch secret_prefix-tools
git branch tools secret_prefix-tools/master
git read-tree --prefix builder/ -u tools:builder
git commit

Or just copy-paste files and commit it :) It is not a git way, but there is no difference at all.

History is everything I need!

This part is more tricky. I didn't found an easy way to do it (probably I was looking for the most tricky one from the beginning, but still).

Get repo

git remote add secret_prefix-tools ssh://[email protected]:1234/secret_prefix-tools
git fetch secret_prefix-tools
git branch tools secret_prefix-tools/master

Filter branch

git filter-branch --prune-empty --subdirectory-filter builder tools

Add subtree (since directory builder/ already exist, create temp directory)

git subtree add --prefix temp tools

Move all files from temp/ to builder/

git commit -m "Move secret_prefix-tools/builder/* files to builder/ folder"