Every turn a shipmates crew member takes is a subprocess. It’s claude or the codex app-server. That in turn spawns shells, go test, npm or whatever the task calls for. Two things have to be true about that tree. When a turn ends or gets killed, the whole tree goes, including the grandchildren. And if somebody sets a memory or CPU budget, the budget applies to the whole tree, not just the process I happened to start.

I have CI that needs Linux amd64, Linux arm64, Windows and macOS. GitHub-hosted runners for all four get expensive fast, especially the arm64 and Mac minutes. Self-hosted runners fix the bill and create a different problem. A stock actions/runner on a box you own runs whatever the workflow says. It keeps whatever the last job left behind. And it’s one fork PR away from somebody running code on your LAN.