HN

Comments (32)

• theodpHN
  52+ years of progress... :-)July, 2026: Google copybara allows one to move code between two prod repositoriesMarch, 1974: IBM COPY allows one to move code between two prod partitioned data sets: OS/MVT and 0S/VS2 TSO Data Utilities COPY, FORMAT, LIST, MERGE User's Guide and Reference https://www.computinghistory.org.uk/downloads/8987
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  klodolph
  Been using this for a while, mostly when I make a tool as part of a larger project and the tool is big enough to deserve its own release.It’s powerful enough to do a whole bidirectional shipping operation where you export and import code—no thanks, that’s a hassle. I use it mostly for a simple fire and forget export, where I take a folder out of its original repo and preserve the history. Then I just move development to the new repo. The new project layout can be completely different, but Git blame works and I’m happy with that.
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  schrodinger
  To those who have used it: is it handy for situations where you have multiple repos that want to share a little code, but it's not worth the trouble of extracting a library, referencing it, publishing versioned releases, updating dependent repos, etc?And instead just "sync" a code folder from one main repo (perhaps containing common domain models) to other repos?Basically the Go philosophy that a little bit of copying is better than a lot of dependency?
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  the_dude_
  If the only need you need is sync repos without exclusions or transformations I wouldn't bother, it could work for you until it doesn't when they archive it or kill it like kaniko or so many other google products/tools.Gitlab has really simple way to mirror from Gitlab to Github or other git vendors/servers
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  MarkSweep
  Some other interesting tools in the space. Rust is using a tool called Josh to sync commits:https://josh-project.devThe 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/fbshipitAny others in this space?
• Gehinnn
  Does this tool allow changes in both repositories? (with a 3 way merge strategy) git subtrees come close, but I have a use case where I need transformations/file filters on top.
• theolivenbaum
  Wild times when one can go from a HN post about an interesting open source code to a port to a new language in a matter of hours (wip, but almost complete: https://github.com/theolivenbaum/copybara)
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  namanyayg
  Nice, I built something similar ~5 years ago using nested git repos and scripts to accomplish a similar purpose of combined private and public repos.My shell script definitely wasn't google scale tho!
• alok-g
  Interesting. Anyone knows how this compares to using git submodules and subtrees?I had used those to create separate repo for website artifacts while the same also remain plugged into the webapp dev repo. (Both sides remain modifiable and changes mergeable to the other side.)Thx.
• xyzzy_plugh
  Copybara is one of those things that you should have set up yesterday.It works great and I've seen many teams gain significant productivity when collaborating in a monorepo with public bits.If you're even toying with an internal monorepo you owe it to yourself to give it a try.
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  jumploops
  We’re in the process of open-sourcing a few sub-projects within a monorepo, and didn’t know this existed!I’m curious what downsides folks have experienced with this tool?Any tips?
• willchen
  i used this tool when i was at google, extremely helpful in open-sourcing things from google3 to github. still, i'm glad to just directly develop on github now :)
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  neprotivo
  If you are using Jujutsu you can achieve a basic way to maintain a public repo from a private monorepo with very little code and without Copybara. I wrote up how to do it here: https://vihren.dev/blog/20260625-jj-public-private-workflow/
• syngrog66
  That seems like a tool easily adoptable by folks engaging in dark patterns on GitHub, particularly the malware bait repos.
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  lysace
  Cute name. (Naming is hard and important.)
• shizuhalabsai
  [flagged]