Julia Evans

homu + highfive: awesome bots that make open source projects easier

Someone described my approach to blogging as “fanfiction” recently, a description that I kind of loved. A lot of the time I write about things that I find in the world that love and my take on them. So here is a small thing I saw that I liked!

The other day I submitted a pull request to an open source project (rust-lang/libc) for the first time in a while and it was a really delightful experience! There were two bots involved and they were both great.

The first thing that happened is rust-highfive-bot commented. It said:

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @alexcrichton (or someone else) soon.

I was like YAY! The aforementioned @alexcrichton responded almost immediately, saying

@bors: r+ 1931ee4


Cool! What is this mysterious r+ 1931ee4 incantation? What is he saying? Basically he’s saying “this looks reasonable; fine with me as long as the tests pass!” Who is @bors?

bors is the Github account of a homu, homu.io bot. Homu’s job is to make it so that you don’t have to keep checking to see if the tests pass! This is a huge blessing on this particular repository because the tests take like an hour. Also, the tests seem to be flaky or something, so they failed a few times and bors took care of rerunning them. here is the pull request, and you can see it getting merged!.

I’m really into homu. It’s the second iteration of a piece of software called bors by Graydon Hoare, and there’s a great blog post talking about it and highfivebot called Rust infrastructure can be your infrastructure.