[Bug]: Error: connect to session bus

[DevWizard13]

Tested versions

I tested both the current dev branch (aea5b57) and the current main branch (aea5b57). This error is reproducible across both of them.

As a note, I am aware that there is another issue surrounding support for other init systems #5 . In this issue, you said to simply install it manually. However, I did that and I still got this problem.

Environment

I recently switched to Artix with s6, a non-systemd distro (which I think is the issue). The dbus is running.

I'm running the (mostly) recommended environment (Wayland+gtk4+niri), as usual. That shouldn't be the problem.

Issue description

I think the fundamental problem here is that I'm running a non-systemd distro, specifically Artix with s6 (recently switched, and it boots nearly instantly). The dbus is running, but UnixNotis doesn't recognize it (and yes, I verified the dbus if running). It should be able to connect to the dbus regardless of if systemd is running. I had to manually install it due to lack of installer support for non-systemd distros.

Steps to reproduce

Try to install it on a non-systemd distro.

Expected behavior

It should find the dbus and connect.

Logs or terminal output

[devwizard@artixlinux UnixNotis]$ cargo run -p unixnotis-daemon
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.06s
     Running `target/debug/unixnotis-daemon`
2026-06-24T18:41:12.260378Z  INFO unixnotis_daemon: configuration loaded config_source="default"
Error: connect to session bus

Caused by:
    0: I/O error: No such file or directory (os error 2)
    1: No such file or directory (os error 2)
[devwizard@artixlinux UnixNotis]$

CSS check output

The bug does not include styling related issues.

Checks

• I searched existing issues before opening this report
• I included enough detail for someone else to try to reproduce the issue
• I tested this on the current master branch or the latest release available to me, or explained why I could not

[locainin]

likely is related to Issue 5 non systemd distros are not supported at this time.

[DevWizard13]

Oh well, I'll add support for s6 myself.

[locainin]

Adding support for other init / non-systemd systems has been on my mind for a while. The main blocker has been accurate testing: I do not run dinit or s6 locally, and this touches more than just the installer.

The core notification stack is not intentionally systemd-only, but the current install and lifecycle flow assumes systemd --user in several places: install paths, service rendering, enable/start/stop, status checks, environment import, daemon detection, and trial-mode restore behavior.

Based on the current tree, the likely files involved are:

• crates/unixnotis-installer/src/paths.rs for service path discovery
• crates/unixnotis-installer/src/actions/install/service.rs for service rendering/start/stop/install
• crates/unixnotis-installer/src/actions/actions_state.rs for installed/enabled/active checks
• crates/unixnotis-installer/src/detect.rs for daemon and service-manager detection
• crates/unixnotis-installer/src/actions/environment/sync.rs for D-Bus/session environment handling
• crates/unixnotis-installer/src/actions/actions_daemon.rs for stopping the active notification owner
• crates/unixnotis-daemon/src/trial_mode/ because restore currently prefers systemd when available

I think a good first step would be a new branch from dev, maybe unixnotis-init-manager??

Since there are several non-systemd setups people may want later, I would rather avoid making this an s6-only patch. The implementation should probably introduce a small init/service-manager layer first, then add s6 as the first non-systemd backend. That should make future support for dinit, OpenRC, runit, or other setups much cleaner instead of duplicating installer logic each time.

For s6 specifically, I would avoid hardcoding one global path until we know the target Artix setup. Upstream s6 expects a service directory with a foreground run script, supervised by s6-supervise, controlled with s6-svc, and inspected with s6-svstat. The important part for this is probably making sure the service gets the correct session env, especially DBUS_SESSION_BUS_ADDRESS and XDG_RUNTIME_DIR.

[locainin]

The branch now exists here: unixnotis-init-manager

I’ll use that branch for the initial non-systemd service-manager work. The plan is to first separate the installer/service lifecycle logic from the current systemd-specific implementation, then use s6 as the first non-systemd backend since #25 is specifically about Artix+s6.

Once that structure is in place, future support for dinit, OpenRC, runit, or other setups should be easier to add without duplicating the same installer logic each time.

[DevWizard13]

Alright, I'll work on it. I think part of the issue might be dbus problems.

[DevWizard13]

So, an update on the situation. The daemon itself seems to require systemd in order to detect the dbus, not just the installer. I tested with another notification daemon, and it works just fine, so I don't think it's a setup specific issue.

I've done some further searching through the code. I believe I've found the issue. In line 120 of crates/unixnotis-daemon/src/main.rs, I've found the error it prints, "connect to session bus". In other words, something went wrong when setting the connection through Connection::session(). The error also says "no such file or directory", so I think it's be searching for a specific file. Do you know what file this is?

[locainin]

The daemon itself seems to require systemd in order to detect the dbus

yes. everything is based around to use systemd; which is why it is a requirement. Please check the newest branch for new development. This is currently being worked on and tested. Removal of systemd being hardcoded has already started, it is being migrated to a new system where other init systems can be added in an easier manner.

dinit appears to be the easiest to start first and some progress has already been made. More progress to come in the next few hours.

[DevWizard13]

Alright, sorry, I thought it was just the installer itself not the daemon. Anyway, I'll work on it in a few days once I have time.

[locainin]

Experimental non-systemd service-manager support is now staged for dev in PR #26:

#26

The PR changelog covers the new backend abstraction plus experimental dinit, runit, and s6 installer paths. This should give us a better base for testing Artix/s6 and related non-systemd setup issues from here.

[DevWizard13]

I'll test the new branch tomorrow.

[DevWizard13]

Ok, so I got a chance to test it. I'll give you more detailed results in a few, but first, there are multiple different ways to set up local s6 service supervision, and UnixNotis assumes that the user went with the more difficult one. I recommend giving the wiki section on local s6 services a read, but I'll give you the TLDR.

There are multiple places a user can set up local services, one of which is /run/$USER/s6-rc and the other is ~/local/share/s6. Setting up the first one requires running s6 as the main system init system and root privileges to set up, but integrates with s6 better, whereas the second can be run on any init system as long as s6-rc is installed locally, and doesn't require root privileges to set up. I recommend adding the second one as a fallback option if /run/$USER/s6-rc doesn't exist. This will also require the database to be updated. I recommend not relying on system scripts such as the one Artix comes with to update it because not all distros will come with it.

I'm currently working on getting full local user supervision set up. I'll give you further updates once that's done. Also, as a side note, it doesn't have the ability to detect pre-existing daemons using the init system, that still requires systemd. I personally think it's better if it stays that way for now, we should focus on core functionality before we work on extra features.

Overall, for a few days of work, this is really good progress so far! I can't wait to see it once it's complete. I'll continue to test. Also, please note that I don't run other init systems and probably won't be able to test it with dinit or others. I attached a screenshot of the installer.

[locainin]

This should now be addressed on dev.

The s6 backend no longer assumes only the integrated /run/$USER/s6-rc layout. It now detects/supports:

• /run/$USER/s6-rc for integrated local supervision
• /tmp/$USER/s6-rc for standalone local supervision
• $HOME/.local/share/s6/rc/live for local-user layouts
• UNIXNOTIS_S6RC_LIVE_DIR for explicit/custom live roots

UnixNotis also no longer relies on Artix helper scripts for the s6 database refresh path. It compiles and updates the local s6-rc database directly with s6-rc-compile and s6-rc-update, then switches the compiled database link itself.

The screenshot’s noisy systemd-error: No such file or directory daemon status rows should also be fixed. Missing systemctl is now treated as systemd daemon detection being unavailable, instead of printing per-daemon errors.

[DevWizard13]

It still doesn't seem to recognize the directories, but this could just as easily be a problem with my system (it's been stubborn). I'll do further debugging tomorrow.