Bug#1108665: override: cron:admin/optional

[Chris Hofstaedtler]

* Richard Lewis  [250703 23:18]:

Cyril Brulebois  writes:

Chris Hofstädtler  (2025-07-02):

in a discussion today on IRC #debian-devel, it was mentioned that
cron is "important". However during the trixie development cycle,
many more packages started installing systemd timer units.



On a default install, I would therefore argue that cron is no longer
very important.


Without any particular hat: I would expect someone wanting to drop
cron


maybe its priority should be demoted to standard, rather than dropping it
entirely?


Nobody asked for removal from the archive. Please read the message 
 Subject: and actually the quoted context.


The point was lowering the Priority: from important to optional.

Chris

Bug#1108665: override: cron:admin/optional

[Antoine Le Gonidec]

Le Thu, 03 Jul 2025 22:17:44 +0100,
Richard Lewis  a écrit :

> >> On a default install, I would therefore argue that cron is no longer
> >> very important.  
> >
> > Without any particular hat: I would expect someone wanting to drop
> > cron  
> 
> maybe its priority should be demoted to standard, rather than dropping it
> entirely?

I assume "to drop" here is meaning to drop from the "Priority: important" base
packages set, to reduce the size of some setups.

Dropping cron from the Debian archive would cause a lot of problems, but I
don’t think this is what is discussed here.


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Bug#1108665: override: cron:admin/optional

[наб]

On Wed, Jul 02, 2025 at 11:24:59PM +0200, Alexandre Detiste wrote:
> Le mer. 2 juil. 2025 à 17:35, Chris Hofstaedtler  a écrit :
> > > Without any particular hat: I would expect someone wanting to drop cron
> > > to come up with some analysis of what remains to be done and what is
> > > going to break if that were to be implemented.
I would like to note that (a) "drop cron" implies
"not having a cron daemon at all" which means an obviously broken system;
sd-cron is an implementation of the cron daemon, which (b) I've been
successfully using exclusively, entirely uneventfully in spite of my
best efforts, for, now, years, on every class of system.

I'd also argue that root mail is likewise a necessity for well-functioning
systems but that's harder to sell in 2025; either way, sd-cron's Suggests:
reflects reality ‒ it can send you mail if you want or it can not,
and you get the failures like any other service failures.
or it can send matrix messages. or whatever via apprise.

Best,


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Bug#1108665: override: cron:admin/optional

[Alexandre Detiste]

Le mer. 2 juil. 2025 à 17:35, Chris Hofstaedtler  a écrit :
> > Without any particular hat: I would expect someone wanting to drop cron
> > to come up with some analysis of what remains to be done and what is
> > going to break if that were to be implemented.

Hi, this has been on the back burner for me for 10 years
and наб did a systematical analysis of all the /etc/cron files
shipped by every single package of the distribution.

The result are the two heuristics table listed here:
   https://wiki.debian.org/systemd-cron

For the other cron jobs it is assumed that the bare name
matches the bare name of the timer.

To check one system in particular, one needs to do

# apt install systemd-cron -y;  systemctl list-timers

This will list two families of .timers :
 - the native ones.
   very common examples:
* dpkg-db-backupt.timer,
* man-db.timer,
* apt-daily.timer,
* fstrim.timer
* e2scrub_all.timer
* ...
- the remaining generated one, from the /etc/cron* files:
   they all live in the cron-x.timer namespace
   and physicaly in /run/systemd/generator/
*  cron-daily-aptitude.timer
*  cron-daily-popularity-contest.timer
*  cron-daily-google-chrome.timer
*  cron-monthly-check-dfsg-status.timer
* ...

Here the non free google-chrome-stable package is the only thing expecting
a cron daemon to be there somehow and going to _break_ a little if
it's not there.

All the packages from the distribution seems to have
the proprer "Depends: cron | cron-daemon" and won't break.

I still think systemd-cron would be a better default for task-laptop;
because it is said that traditional cron or the one in Debian would wake up
the system every single minute to poll /etc
& /var/lip/spool/cron/crontabs which is bad. I don't have hard proof for this.

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=915370#101


> Relatedly, cron Recommends: default-mta | mail-transport-agent,
> which we kinda also no longer expect to be installed by default on a
> default install anymore. Due to how debootstrap works today, the
> Recommends: is very often not fulfilled. Nevertheless I doubt we
> still expect an MTA to be part of the default install.

That's the reason why systemd-cron Suggests: a MTA
instead of Recommending one; so that people
doing the switch do not get an extra MTA they don't what.
If they wanted one they would have installed it already.

A pre-installed MTA is fully supported.

Greetings

Bug#1108665: override: cron:admin/optional

[Chris Hofstaedtler]

On Wed, Jul 02, 2025 at 05:29:58PM +0200, Cyril Brulebois wrote:
> Hi,
> 
> Chris Hofstädtler  (2025-07-02):
> > in a discussion today on IRC #debian-devel, it was mentioned that 
> > cron is "important". However during the trixie development cycle, 
> > many more packages started installing systemd timer units.
> > On a default install, I would therefore argue that cron is no longer
> > very important.
> 
> Without any particular hat: I would expect someone wanting to drop cron
> to come up with some analysis of what remains to be done and what is
> going to break if that were to be implemented.

I pondered that, but packages have to depend on cron anyway if they 
want it. cron is not Essential: yes.

> Also, at this stage of the release cycle, really?

Seemed like reconsidering the cron prio was forgotten, but from my 
PoV it doesn't matter if it happens for trixie or forky.

> Cc-ing debian-devel@ so that this gets discussed there.

Thanks.

Chris

Bug#1108665: override: cron:admin/optional

[Cyril Brulebois]

Hi,

Chris Hofstädtler  (2025-07-02):
> in a discussion today on IRC #debian-devel, it was mentioned that 
> cron is "important". However during the trixie development cycle, 
> many more packages started installing systemd timer units.
> On a default install, I would therefore argue that cron is no longer
> very important.

Without any particular hat: I would expect someone wanting to drop cron
to come up with some analysis of what remains to be done and what is
going to break if that were to be implemented.

Also, at this stage of the release cycle, really?

Cc-ing debian-devel@ so that this gets discussed there.


Cheers,
-- 
Cyril Brulebois (k...@debian.org)
D-I release manager -- Release team member -- Freelance Consultant


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Bug#1108665: override: cron:admin/optional

[Chris Hofstädtler]

Package: ftp.debian.org
Severity: normal
X-Debbugs-Cc: c...@packages.debian.org, debian-b...@lists.debian.org
Control: affects -1 + src:cron
User: ftp.debian@packages.debian.org
Usertags: override

Hi,

in a discussion today on IRC #debian-devel, it was mentioned that 
cron is "important". However during the trixie development cycle, 
many more packages started installing systemd timer units.
On a default install, I would therefore argue that cron is no longer 
very important.

Relatedly, cron Recommends: default-mta | mail-transport-agent, 
which we kinda also no longer expect to be installed by default on a 
default install anymore. Due to how debootstrap works today, the 
Recommends: is very often not fulfilled. Nevertheless I doubt we 
still expect an MTA to be part of the default install.

Thanks,
Chris