Building Debian image on Arch host fails: depmod: not found (or modinfo)

[johnp789]

I'm using Arch locally, and building a Debian Trixie image using Arch tools fails with

Processing triggers for shim-signed:amd64 (1.47+15.8-1) ...
‣  Running depmod for 6.12.57+deb13-amd64
‣ depmod not found.

or with

‣  Creating cpio archive /var/tmp/mkosi-workspace-52rjgimx/microcode.initrd…
‣  Building kernel modules initrd
‣  Running modinfo to fetch kernel module dependencies
‣ modinfo not found.

Following the discussion in #1368, I tried adding /sbin:/usr/lib/systemd to my PATH, and the image build succeeded. I'm not sure what might be in those directories that is missing, since depmod and modinfo are both in /usr/bin:

# ls -l $(which depmod) $(which modinfo) /usr/bin/kmod
lrwxrwxrwx 1 root root      4 Aug 26  2024 /usr/bin/depmod -> kmod
-rwxr-xr-x 1 root root 166080 Aug 26  2024 /usr/bin/kmod
lrwxrwxrwx 1 root root      4 Aug 26  2024 /usr/bin/modinfo -> kmod

[athenacfr]

I had to add export PATH=$PATH:/sbin:/usr/lib/systemd to my profile.

maybe #1368 needs to be reopen?

[DocSneider]

I have the same issue, using EndeavourOS (Archlinux) as host, Distribution=debian and ToolsTreeDistribution=debian.

If I run mkosi with the following mkosi.conf (and other additional .conf files in mkosi.conf.d):

[Distribution]
Distribution=debian
Release=trixie
Repositories=main,contrib,non-free,non-free-firmware

[Output]
Format=disk
ImageId=mkosi-debian-uki

[Build]
ToolsTree=yes
ToolsTreeDistribution=debian
CacheDirectory=mkosi.cache
Incremental=yes
History=yes

[Content]
# Boot configuration
Bootable=yes
Bootloader=uki

# System configuration
Autologin=no
RootPassword=root
Timezone=UTC
Locale=C.UTF-8

# Kernel command line: classic eth0 naming, serial console
KernelCommandLine=
    console=ttyS0,115200n8
    console=tty0
    net.ifnames=0
    biosdevname=0

# Clean up package manager metadata
CleanPackageMetadata=yes

[Validation]
# SecureBoot signing (keys generated with: mkosi genkey)
SecureBoot=yes
SecureBootAutoEnroll=yes

[Runtime]
# QEMU configuration for testing
RAM=2G
KVM=yes

I also get the error depmod not found and the build fails.

Detailed part of the Log

[...]
Processing triggers for initramfs-tools (0.148.3) ...
‣  Running depmod for 6.12.73+deb13-amd64
‣ + depmod --all 6.12.73+deb13-amd64
‣ depmod not found.
‣ + rm -rf -- /work/home/USER/.cache/mkosi/mkosi-workspace-1mp6fxvi
Traceback (most recent call last):
  File "/usr/lib/python3.14/site-packages/mkosi/run.py", line 246, in spawn
    proc = subprocess.Popen(
        [*setup, *prefix, *cmdline],
    ...<15 lines>...
        preexec_fn=_preexec,
    )
  File "/usr/lib/python3.14/subprocess.py", line 1038, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
    ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                        pass_fds, cwd, env,
                        ^^^^^^^^^^^^^^^^^^^
    ...<5 lines>...
                        gid, gids, uid, umask,
                        ^^^^^^^^^^^^^^^^^^^^^^
                        start_new_session, process_group)
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.14/subprocess.py", line 1989, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'depmod'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.14/site-packages/mkosi/run.py", line 52, in uncaught_exception_handler
    yield
  File "/usr/lib/python3.14/site-packages/mkosi/run.py", line 92, in fork_and_wait
    target(*args, **kwargs)
    ~~~~~~^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.14/site-packages/mkosi/__init__.py", line 4903, in run_build
    build_image(
    ~~~~~~~~~~~^
        Context(
        ^^^^^^^^
    ...<7 lines>...
        )
        ^
    )
    ^
  File "/usr/lib/python3.14/site-packages/mkosi/__init__.py", line 3984, in build_image
    run_depmod(context, cache=True)
    ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.14/site-packages/mkosi/__init__.py", line 3046, in run_depmod
    run(["depmod", "--all", modulesd.name], sandbox=chroot_cmd(root=context.rootoptions))
    ~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.14/site-packages/mkosi/run.py", line 152, in run
    with spawn(
         ~~~~~^
        cmdline,
        ^^^^^^^^
    ...<8 lines>...
        sandbox=sandbox,
        ^^^^^^^^^^^^^^^^
    ) as process:
    ^
  File "/usr/lib/python3.14/contextlib.py", line 141, in __enter__
    return next(self.gen)
  File "/usr/lib/python3.14/site-packages/mkosi/run.py", line 266, in spawn
    die(f"{e.filename} not found.")
    ~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.14/site-packages/mkosi/log.py", line 24, in die
    sys.exit(1)
    ~~~~~~~~^^^
SystemExit: 1
‣ + tput cnorm
‣ + tput smam
Script done.

But if I run export PATH=$PATH:/sbin:/usr/lib/systemd; mkosi build the build works.