Bug#1133276: mkosi: Building Debian Images fails (kmod not found)

[Manuel Traut]

Hi Luca,

Am 2026-04-14 13:41, schrieb Luca Boccassi:
> Control: close -1
> 
> Please stop playing ping-pong with the BTS. This is an issue on your
> setup, regardless of whatever is the right option or env var to set.

I've just seen, that it was also reported upstream: 
https://github.com/systemd/mkosi/issues/1368#issuecomment-4069166111

As mentioned it is fixed in latest upstream git and not reproducible 
with the version in trixie.
I also really don't like the ping-pong. But this is definitely a bug in 
the 26 release.

Bisecting mkosi points to this:

--8<--
commit 88a91f5053ca6919d39948a7c23c798225900518 (HEAD)
Author: Daan De Meyer <daan.j.demeyer at gmail.com>
Date:   Tue Dec 23 17:17:01 2025 +0100

     run: Call execvpe() from preexec function

     Python does its own executable lookup in $PATH before executing the 
preexec function, and
     hence before we have set up the sandbox which influences the lookup 
results. To get around
     that, let's call execvpe() ourselves inside the preexec() function, 
and not give Python the
     chance to do it itself. This ensures we can do the proper executable 
lookup after setting
     up the sandbox. If we can't find the executable, do nothing, and let 
Python do its own
     search logic so it can return a proper error, which we cannot do 
from the preexec function.
     Note that by doing this we also skip Python closing all open file 
descriptors except the
     ones specified by the user in pass_fds, but since Python opens all 
file descriptors with
     O_CLOEXEC anyway, we'll assume we're good and don't need to close 
open file descriptors
     explicitly.
--8<--

I picked the attached patch in d/patches and the so built package is 
fine. If you want I can create a MR in salsa for this.

cheers
Manuel
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