Background processes in scripts are not terminated

[ValdikSS]

mkosi commit the issue has been seen with

25.3, 26

Used host distribution

Fedora 43, Arch Linux

Used target distribution

Debian 13

Linux kernel version used

6.17.12-300.fc43.x86_64

CPU architectures issue was seen on

x86_64

Unexpected behaviour you saw

If build or postinst script run any process in the background, mkosi does not terminate these processes upon exiting the script/sandbox/image building process.

Applies to both regular host scripts and .chroot scripts.

Used mkosi config

# cat <<EOF >mkosi.postinst
#!/bin/bash
sleep 600 &
exit 0
EOF

# chmod +x mkosi.postinst

# mkosi -d debian -r trixie -t directory

mkosi output

# mkosi -d debian -r trixie -t directory

‣ Validating certificates and keys
‣ Syncing package manager metadata
…
‣ Building main image
‣  Installing Debian
…
‣  Running postinstall script /root/b/mkosi.postinst…
‣  Generating system users
‣  Generating volatile files
‣  Applying presets…
‣  Generating hardware database
No hwdb files found, skipping.
‣  /root/b/image size is 103.0M.


mkosi finished here.

On the host:
# ps aux
root        2904  0.0  0.0   3260  2172 pts/0    S    23:25   0:00 sleep 600

[daandemeyer]

This is not something we guarantee. It would also be a pain to implement.

[ValdikSS]

It would also be a pain to implement.

Terminate all the processes in .scope?

[ValdikSS]

Using the following hack now:

systemd-run --scope -u mkosiscope bash -c 'mkosi …; systemctl stop mkosiscope.scope'