No network available during task do_install on debian bullseye/5.10 host - but on a debian buster/4.19 host network is available

["Kaufmann, Bjoern" <bjoern.kaufmann@siemens.com>]

Hello,

I have the following recipe my-recipe_2023.1.bb:

inherit dpkg-raw

do_install() {
        ip a
}

I run a build based on isar "d26660b724b034b602f3889f55a23cd9be2e87bd" (> v0.9, < v0.10-rc1) inside of a docker container "ghcr.io/siemens/kas/kas-isar:3.3".

_____

In the first scenario the build runs inside the docker container on a debian buster VM with 4.19.0-26 kernel. In this scenario the logfile "build/tmp/work/debian-bullseye -amd64/my-recipe/2023.1-r0/temp/log.do_install" looks as follows:

DEBUG: Executing shell function do_install
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
944: eth0@if945: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether 02:42:ac:11:00:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.3/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever
DEBUG: Shell function do_install finished

_____

In the second scenario the exact same build runs inside the docker container on a debian bullseye VM with 5.10.0-28 kernel. In this scenario the logfile "build/tmp/work/debian-bullseye -amd64/my-recipe/2023.1-r0/temp/log.do_install" looks as follows: 

DEBUG: Executing shell function do_install
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
DEBUG: Shell function do_install finished

_____


I would like to understand why the same build behaves differently on the two different host systems. Thanks in advance.

Best regards,
Bjoern