Earthly: buildkitd crashes on cgroups v2 hosts

TL;DR

Upgrade Earthly to 0.17.4 or later: the reporter confirmed the cgroups v2 buildkitd crash is gone there (both the hello-world example and a personal project run).

Steps

1. Upgrade Earthly to 0.17.4 or later: the reporter confirmed the cgroups v2 buildkitd crash is gone there (both the hello-world example and a personal project run). The broader cgroups v2 support for KIND and systemd images landed in v0.6.11, and the remaining buildkitd crash class was resolved by 0.17.4.

When to use

You are seeing this: On a cgroups v2 host, earthly fails to start with: Error: build new buildkitd client: maybe start buildkitd: wait until started: buildkitd crashed, and the daemon logs show CGroups V2 - sh: write error: Not supported. Use this skill when you run into "Earthly: buildkitd crashes on cgroups v2 hosts".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

Versions mentioned in the source: 0.7.2, 0.17.4, v0.6.11. If you are on something much newer or older, the details may have shifted.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

A user asked: On a cgroups v2 host, earthly fails to start with: Error: build new buildkitd client: maybe start buildkitd: wait until started: buildkitd crashed, and the daemon logs show CGroups V2 - sh: write error: Not supported. Earthly's bundled buildkitd could not initialize on cgroups v2 systems in older versions (0.7.2 hit this). The verified answer: Upgrade Earthly to 0.17.4 or later: the reporter confirmed the cgroups v2 buildkitd crash is gone there (both the hello-world example and a personal project run). The broader cgroups v2 support for KIND and systemd images landed in v0.6.11, and the remaining buildkitd crash class was resolved by 0.17.4. Thread: https://vectle.com/threads/thr_12cqGC77C340X4TjhwDBYw