Bug#950504: gdm3 reproducibly gets stuck upon boot with nomodeset kernel setting

[Md Ayquassar]

Package: gdm3
Version: 3.30.2-3
Severity: important
Dear Maintainer,
Upon booting with nomodeset kernel setting on GRUB command line, my laptop T42
reproducibly gets stuck at "Started GNOME Display Manager.". (As to what happens
without nomodeset, cf. http://bugs.debian.org/948288 : there is one more bug, a
segfault, there there to think about.)
In this state, the laptop persists for an indefinite duration (more than a few
minutes). To let the boot process continue, I switch to some tty, say, with
Ctrl+Alt+F2, and then I switch back with Ctrl+Alt+F1. Then, the boot process goes
on and, finally, I obtain a GDM login screen, being able to start work without
observable ill effects; during work, Xorg is reported as the chosen display
server:

$ env| grep -i x11
XDG_SESSION_TYPE=x11
The installation is more-or-less FRESH (using netinst i386) and up to date.

How do I get rid of the manual intervention during boot for gdm3? If I ship this
to a client, the client would say "system unusable". Of course, one can use
lightdm instead of gdm3 (which does start without visible issues) as a
workaround, but, in this bug report, we deal with gdm3 specifically.

The log files are attached. Some more data:

guest at T42-LAPTOP:/tmp$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 10 (buster)
Release: 10
Codename: buster
guest at T42-LAPTOP:/tmp$ uname -a
Linux T42-LAPTOP 4.19.0-6-686 #1 SMP Debian 4.19.67-2+deb10u2 (2019-11-11) i686
GNU/Linux
guest at T42-LAPTOP:/tmp$
Thanks in advance,
Md Ayquassar
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