cronie: prevent from failing without sendmail

[raindev]

If a job produces output cronie will attempt to send it's output with
sendmail, failing if the command doesn't exist. sendmail failures are
not handled gracefully and will result in remaining cron scripts to not
be executed. The change makes cronie service use syslog so cron jobs
that produce output are working out of the box.

General

• This is a new package and it conforms to the quality requirements

Have the results of the proposed changes been tested?

• I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
• I generally don't use the affected packages but briefly tested this PR

Does it build and run successfully?

(Please choose at least one native build and, if supported, at least one cross build. More are better.)

• I built this PR locally for my native architecture, (x86_64, glibc)
• I built this PR locally for these architectures (if supported. mark crossbuilds):
  • aarch64-musl
  • armv7l
  • armv6l-musl

[ericonr]

Missing revbump ;)

[paper42]

-s makes cronie log to syslog instead of sendmail even if sendmail is installed, that's probably not what users expect and it would be a breaking change. A proper fix would be to either add sendmail to dependencies or make a patch which fixes this and submit it upstream. but:

Fedora removed sendmail from dependencies in 2010 and they still don't have it:

remove sendmail from requirements. If it's not installed, it will log into (r)syslog.

[raindev]

Ah, so cronie does handle missing sendmail gracefully. I wrongly assumed the reason one of the jobs is not run was sendmail but it turned out to be the fact that cronie uses run-parts to start job scripts, which silently ignores scripts with a . in the file name. From run-parts(8):

the names must consist entirely of ASCII upper- and lower-case letters, ASCII digits, ASCII underscores, and ASCII minus-hyphens.

Other files and directories are silently ignored.