Perhaps cron doesn’t get used much anymore, but Gentoo’s vixie-cron is broke. Vixie-cron works just fine as a daemon executing commands in /etc/cron.*, but for the user it’s not. Yes I was sure to be added to the cron and crontab group, followed Gentoo Cron Tutorial, but vixie-cron would bark, “Permission Denied” when I tried to edit the crontab. The only way I could fix this as user was to change the permission of /var/spool/cron/crontabs to that of user:crontab this however broke it for the daemon – a problem I could not recover from. I re-installed vixie-cron to no effect.
I would report this as a bug but I happened to look at vixie-cron details on it’s ftp and discover it hasn’t been updated for 3 years so I’m not going to bother. The Gentoo Cron Tutorial actually references dcron and fcron more often so I imagine Gentoo is going away from it. Anyways, I got fcron installed and it works nicely, tyvm.
Fcron is a built with a slightly more ambitious than vixie choosing, for example, to rather to use a binary for a system crontab and not the standard /etc/crontab. Gentoo developer jer provides some nice instructions in the ebuild to adapting the system. I took the time to write in plain text his instructions and put it on the wiki.