Oliver Freyermuth <freyermuth@physik.uni-bonn.de> (2023-04-09):
> Likely, that's indeed since stuff has already happened at that point.
> It seems that the newly added "if" worked as expected, so it must have
> been "(none)" at the time of checking, and only changed to "?"
> afterwards.
I've just verified that part, and I'm now quite convinced that checking
for “(none)” is fine:
- right at the beginning, on the language selection screen, one can “go
back” and get a shell. There, `uname -a` returns:
Linux (none) 6.1.0-3-amd64 […]
- once network discovery has happened, including DHCP, and once the
hostname prompt is presented, `uname -a` returns:
Linux 6.1.0-3-amd64 […]
So there was definitely some hostname set at the very beginning, on the
kernel side, and that can be used by env2debconf via hostname without
passing any options, which leverages busybox's safe_gethostname() which
taps into UTS information, which is set an contains “(none)”.
While I'm not sure *what* happens, later on it seems the hostname part
is unset, which leads safe_gethostname() to fail and extract the
hostname, and which ends up returning “?” instead.
If there was any doubt regarding stability, include/linux/uts.h
(linux.git) is almost all dating back all the way to the mother git
commit (2005), with UTS_NODENAME being an exception (2011):
bd5dc17be87b3 (Josh Triplett 2011-06-15 15:08:28 -0700 13) #define UTS_NODENAME CONFIG_DEFAULT_HOSTNAME /* set by sethostname() */
See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bd5dc17be87b3a3073d50b23802647db3ae3fa8e
And the kernel packaging started setting this option back in 2015:
commit 8f0f730e419302af8dc8a6c043363ba300e9fac1
Author: Ben Hutchings <benh@debian.org>
Date: Wed Jul 29 02:29:09 2015 +0000
Explicitly set various config symbols to defaults
svn path=/dists/trunk/linux/; revision=22870
Seeing how the issue was brought up to my attention by one of the kernel
maintainer in Debian, I hope this default value won't change or we'll be
told if that happens (hint hint wink wink)!
Cheers,
--
Cyril Brulebois (kibi@debian.org) <https://debamax.com/>
D-I release manager -- Release team member -- Freelance Consultant
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