Bug#1143094: hw-detect: Fails to detect network card under BIOS boot in qemu

Roland Clobus <[email protected]> Thu, 30 Jul 2026 12:56:16 +0200
Newsgroups	gmane.linux.debian.devel.bugs.rc
Message-ID	<[email protected]>
Source: hw-detect
User: [email protected]
Usertags: amd64
X-Debbugs-Cc: [email protected]
User: [email protected]
Usertags: amd64
X-Debbugs-Cc: [email protected]
Version: 1.176
Severity: grave
Justification: renders package unusable
Tags: d-i

Hello maintainers of hw-detect,

The new version of ethdetect.sh does not detect the network interfaces when booting from BIOS.

This can be seen on openQA [1] where the installer fails to find the network interfaces for the BIOS scenarios. The UEFI scenarios still work.

 From the d-i syslog (broken, BIOS) [2]:
Jul 29 21:33:12 main-menu[430]: INFO: Menu item 'ethdetect' selected
Jul 29 21:33:17 net/hw-detect.hotplug: Detected hotpluggable network interface lo
Jul 29 21:33:18 net/hw-detect.hotplug: Detected hotpluggable network interface ens4
Jul 29 21:33:18 kernel: [   30.969705] virtio_net virtio0 ens4: renamed from eth0
Jul 29 21:33:19 check-missing-firmware: looking at dmesg for the first time
Jul 29 21:33:19 check-missing-firmware: saving timestamp for a later use: [   30.969705]
Jul 29 21:33:19 check-missing-firmware: no missing firmware in loaded kernel modules

 From the d-i syslog (last working, BIOS) [3]:
Jul 29 16:03:07 main-menu[430]: INFO: Menu item 'ethdetect' selected
Jul 29 16:03:13 net/hw-detect.hotplug: Detected hotpluggable network interface lo
Jul 29 16:03:13 kernel: [   31.465192] virtio_net virtio0 ens4: renamed from eth0
Jul 29 16:03:13 net/hw-detect.hotplug: Detected hotpluggable network interface ens4
Jul 29 16:03:14 check-missing-firmware: looking at dmesg for the first time
Jul 29 16:03:14 check-missing-firmware: saving timestamp for a later use: [   31.465192]
Jul 29 16:03:14 check-missing-firmware: no missing firmware in loaded kernel modules
Jul 29 16:03:14 check-missing-firmware: taking network interface ens4 up/down
Jul 29 16:03:15 check-missing-firmware: looking at dmesg again, restarting from timestamp: [   31.465192]
Jul 29 16:03:15 check-missing-firmware: timestamp found, truncating dmesg accordingly
Jul 29 16:03:15 check-missing-firmware: keeping timestamp (no new lines): [   31.465192]
Jul 29 16:03:15 check-missing-firmware: no missing firmware in loaded kernel modules

After 1.176 entered unstable, all BIOS installer tests started to fail. There are no version differences in the other udebs, so that's why I report against hw-detect.

I think it might be caused by the 'Change hw-detect/firmware-lookup type to string' change, since that influences whether the network interface is taken down and up again.

With kind regards,
Roland Clobus

[1] https://openqa.debian.net/tests/overview?build=20260729-7&distri=debian&version=testing
[2] https://openqa.debian.net/tests/554214/logfile?filename=syslog.txt
[3] https://openqa.debian.net/tests/554110/logfile?filename=complete_install-DI_syslog.txt
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