bug#73110: 29.4; emacs.service failed with result 'timeout'

["Björn Bidar via Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Patrick Nicodemus <gadget142@gmail.com> writes:

> Neither Eli or I proposed supporting this use case (using systemd as a
> service without compiling with support for libsystemd)

I didn't mean to say literally supporting but more like if there's a bug
from such a use case than it shouldn't be worth investing time in.

> I think it's perfectly valid to ask the user to compile Emacs with
> libsystemd support for this to work. Thus, this is a documentation bug.

Now looking at the service again made find the issue I think.
The service uses 'Type=notify' which means that Emacs has to tell
systemd that it is ready.

To quote systemd.service(5):

> Behavior of notify is similar to exec; however, it is
> expected that the service sends a "READY=1" notification
> message via sd_notify(3) or an equivalent call when it has
> finished starting up. systemd will proceed with starting
> follow-up units after this notification message has been
> sent. If this option is used, NotifyAccess= (see below)
> should be set to open access to the notification socket
> provided by systemd. If NotifyAccess= is missing or set to
> none, it will be forcibly set to main.

> Systemd is able to manage many programs on my computer without them being
> compiled with a special support for libsystemd, so I do not expect to
> require a special additional library to get Emacs to work if the
> documentation does not mention it.

It is able to but if a program opts into systemd features such
as notify it has to also support them.

> Chapter 40 of the manual does not indicate that running Emacs as a server
> is special non-core functionality, therefore as a user I assume that if
> this functionality is not working then it is broken, not that I
> misconfigured it at compile time. If this is supposed to be core
> functionality then the build should fail loudly if the dependencies are not
> found at compile time unless the user supplies the --without-libsystemd
> flag.

The service file would have to use another Type such as 'exec'
if not compiled with libsystemd support enabled during build.

>
> On Sun, Oct 13, 2024, 7:26 AM Björn Bidar <bjorn.bidar@thaodan.de> wrote:
>
>> Eli Zaretskii <eliz@gnu.org> writes:
>>
>> >> From: Patrick Nicodemus <gadget142@gmail.com>
>> >> Date: Sat, 7 Sep 2024 13:22:30 -0400
>> >>
>> >> I want to run Emacs as a service and connect to it with a client. I
>> >> followed the instructions here:
>> >>
>> >>
>> https://www.gnu.org/software/emacs/manual/html_node/emacs/Emacs-Server.html
>> >>
>> >> and ran the command
>> >> systemctl --user enable emacs
>> >>
>> >> This apparently creates a file at
>> >> ~/.config/systemd/user/default.target.wants/emacs.service
>> >> For some reason emacs is not successfully communicating to systemd that
>> >> it has launched successfully, and so systemd terminates emacs.
>> >
>> > According to this:
>> >
>> >> Configured features:
>> >> ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ
>> >> IMAGEMAGICK JPEG JSON LCMS2 LIBSELINUX LIBXML2 MODULES NATIVE_COMP
>> >> NOTIFY INOTIFY PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
>> >> TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XIM XWIDGETS GTK3 ZLIB
>> >
>> > your Emacs is built without libsystemd support, which I think is
>> > required for this to work?  Or maybe I'm missing something.
>>
>> I don't know exactly if libsystemd is required for the service to work,
>> I think it shouldn't however, but why?
>> Why would use the systemd user service but also not built with
>> libsystemd?
>> Even if there's something wrong why support such as usecase?
>>


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