`docker create` drops /.dockerenv into the container's writable layer,
and `docker export` includes it in the tar. When systemd later boots
that rootfs it finds /.dockerenv and flags virtualization=docker,
which disables a bunch of udev device-unit behaviour (device units
never become active, mount units waiting on them hang forever).
Strip /.dockerenv (and /run/.containerenv for podman symmetry) from
the staging tree after FlattenTar and before BuildExt4 so systemd
correctly detects virtualization=kvm.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Thales Maciel
66838bb135