fbshipit

Some other interesting tools in the space. Rust is using a tool called Josh to sync commits: https://josh-project.dev The blog post from the Rust people: https://blog.rust-lang.org/inside-rust/2026/06/04/how-josh-h... Meta used to have an open source tool called fbshipit. But according to its open source repo they no longer use it: https://github.com/facebookarchive/fbshipit Any others in this space?

Facebook uses a monorepo, similar to the way Google does it. Dependencies are vendored and checked into the repo. Facebook has released a tool for migrating software between repos, which is much like Google's Copybara: Facebook's fbshipit: https://github.com/facebook/fbshipit Google's copybara: https://github.com/google/copybara With these tools, you can make fairly sophisticated choices about how you do vendoring. You can make the internal version look just like the public version, in terms of commit history. And you can export internal commits to public commits, stripping out confidential information along the way (or integrations with internal systems and tooling).

There are a few tools to split commits from sub-dirs to a branch which you can then push to a public repo/monorepo. E.g. `git subtree`, https://github.com/facebook/fbshipit, https://github.com/splitsh/lite, https://github.com/ingydotnet/git-subrepo. A lot of these approaches though rely on the source-of-truth being the internal company monorepo. PRs are synced internally, merged, and then pushed out. It means that someone outside the organization cannot be a maintainer, and the speed of PR merges is dictated by the available resources inside the company. So I'd argue this is not the right OSS way of doing things. Even if there are two public monorepos out in the open you can have similar problems trying to collaborate, because to modify one line of a package, you may need to pull a huge monorepo and its tooling down. Does anyone have a so

People at Facebook who use both internal repos and external ones (like me) need to know both hg and git. It's not too hard; the two provide similar functionality and many of our hg extensions (https://bitbucket.org/facebook/hg-experimental) make hg more git-like in some ways. Most of our open source projects also use an in-house tool "fbshipit" https://github.com/facebook/fbshipit to automatically export internal commits to open source so if you make changes that happen to touch an open source project but it's not your primary focus then you can work entirely in the internal (hg) repo and your changes get copied out automatically.

What Facebook uses internally in their monorepo and what they publish to open source for external consumption doesn't have to be the same build tool. Facebook uses fbshipit (https://github.com/facebook/fbshipit/) to take slices of their monorepo and publish them to GitHub.