Indeed, it will still download and install it. It is unsuitable because after the mail was sent it can already be too late and it can take lots of network bandwidth. This can be problematic for various reasons.
On 2020-08-03 15:10, Stuart Henderson wrote: > On 2020/08/03 13:50, Solene Rapenne wrote: >> On Mon, 3 Aug 2020 13:28:38 +0200 >> Emil Engler <m...@emilengler.com>: >> >>> ## Abstract >>> This patch adds an argument to sysupgrade(8) which makes it possible >>> to check if an upgrade is available, similar to "syspatch -c". >>> This works both, for snapshots and releases. >>> >>> ## Usage >>> Add "-c" to sysupgrade. >>> If the script exits with a zero, an upgrade is available. If it fails >>> you are already on the newest version or an upgrade cannot be pulled >>> for whatever reason. >>> >>> ## Motivation >>> I want a cronjob on my desktop (which is on -current) that checks >>> regularly if a new snapshot is available and notifies me if this is >>> the case. syspatch(8) already has such a feature, so why not add >>> one to sysupgrade? Also it could be useful on -stable and -release >>> systems. >> >> it seems to me you could use this in your crontab >> >> sysupgrade -n | grep "Already on last snapshot" || sh >> send_mail_new_snasphot.sh >> > > That won't just check, it will stage the release for install on next boot. >