systemd.path: DirectoryNotEmpty doesn't trigger for files starting with .

[antifuchs]

systemd version the issue has been seen with

255

Used distribution

NixOS 23.11

Linux kernel version used

6.6.30

CPU architectures issue was seen on

x86_64

Component

systemd

Expected behaviour you didn't see

I have a systemd.path defined with a clause DirectoryNotEmpty=/data/transfers/ready - when a regular file with any name at all gets created in the directory, a transfer should be triggered. I was expecting files matching any glob pattern, visible or hidden, to trigger the trigger-transfer.service to be started.

Unexpected behaviour you saw

I do see the trigger-transfer.service being started for regular files starting with any character that isn't the . - but "hidden" / "dot" files like .foo inside the directory do not start the service.

Steps to reproduce the problem

1. Make a unit like the following:

# /etc/systemd/system/trigger-transfer.path
[Path]
DirectoryNotEmpty=/data/transfers/ready
Unit=trigger-transfer.service

[Install]
WantedBy=multi-user.target

2. Create a oneshot unit named trigger-transfer.service (not shown)
3. Run touch /data/transfers/ready/foo - the service gets started
4. Run touch /data/transfers/ready/.foo - the service does not get started.

Additional program output to the terminal or log subsystem illustrating the issue

No response

[YHNdnzj]

This is intended behavior, and it's consistent with ConditionDirectoryNotEmpty=: #23220.

But such behavior is not documented, which is something we should fix.

[antifuchs]

Ah, that makes sense. Is there a way to opt into hidden files triggering a start? (Documented or undocumented...)