Moo is a brand new internal tool we use to moove faster and thought we'd share it.
Every branch or agent attempt gets its own isolated Linux machine, and the machine's state is versioned with your repo. Moo save snapshots the runtime tagged with the current commit. Check out an old SHA, run moo new, and you boot the exact runtime that existed there.
It's microVMs with copy-on-write (CoW) disks under the hood. Forking a 20 GB environment is <500ms.
Right now it's only macOS Apple Silicon only due to depending on libkrun and APFS clonefile.