Today for Paciffic time zone (PST) was the DST change, going one hour back. I have two Gentoo installations, both ran the /etc/cron.daily scripts twice. Reproducible: Didn't try Steps to Reproduce:
And why is that a Gentoo bug?
Well, good question. One would expect that the daily cron should not run twice within one hour, because of the /var/spool/cron/lastrun/cron.daily lock file. I am thinking that there is probably something wrong in /usr/sbin/run-crons. It is creating the /var/spool/cron/lastrun/cron.daily, which is used to make sure that the daily scripts are not run twice, right? This should work even if the time changes by one hour back. The only thing I can think of is that the final "find -newer" is deleting the lock file when the time changes and therefore the cron is run again... In other words, I think the reason for the double execution is somewhere in /usr/sbin/run-crons.
I assume you are using vixie-cron, right? This is an "upstream" bug or "feature", not something Gentoo-specific. See 'man 5 crontab' <snip> The format of a cron command is very much the V7 standard, with a number of upward-compatible extensions. Each line has five time and date fields, followed by a user name if this is the system crontab file, followed by a command. Commands are executed by cron(8) when the minute, hour, and month of year fields match the current time, and when at least one of the two day fields (day of month, or day of week) match the current time (see 'Note' below). Note that this means that non-existant times, such as "missing hours" during daylight savings conversion, will never match, causing jobs scheduled during the "missing times" not to be run. Similarly, times that occur more than once (again, during daylight savings conversion) will cause matching jobs to be run twice. </snip> Marking INVALID, according to man page this is an expected behaviour.
I run vixie-cron, and you are completely correct about the man page. But let's note that run-parts is executed every 10 minutes, ant that does not cause double execution of any of the /etc/cron.* scripts. Therefore, simply because cron would run run-parts "twice" should not cause double execution of daily tasks (not to mention the meaning of "twice" in this case is pointless, because run-parts is executed every 10 minutes anyway, as mentioned double execution is prevented via a lock file). Because the time changes back, something in the lock logic does not work as expected -- otherwise it should never execute a daily task within the same hour. Please do not close the bug. Give me a week, I will try to reproduce the problem and understand why the lock file does not work as expected. I will update this issue when I get more information.
The main bug here is DST existence. :=) NEEDINFO, reopen when you find out something.
Reopen to dupe this...
*** This bug has been marked as a duplicate of 69777 ***
