Short IT recipes: gentoo and distrobox: OCI runtime exec failed: exec failed: unable to start container process: error starting setns process: exec: already started

Friday, May 08, 2026

I have gentoo host, with systemd, nvidia and docker. When I want to create a distrobox image with systemd in the container, e.g.:


  distrobox create --nvidia -i archlinux -n abox -H ~/home-abox --init --additional-packages "systemd"

I was getting:


  OCI runtime exec failed: exec failed: unable to start container process: error starting setns process: exec: already started

The solution was to use crun container runtime, instead of default runc. To do this

1. Install crun:


  emerge -av app-containers/crun

2. Create `/etc/decker/daemon.json` with the content:


  {

  "runtimes": {

    "crun": {

      "path": "/usr/bin/crun"

    }

  },

  "default-runtime": "crun"

}

3. Restart docker


  sudo systemctl restart docker