Comment 61 for bug 349469

This is on Debian, but I think it is the same kind of problem.

# pstree -alps 27393
init,1
  └─cron,8085
      └─cron,25543
          └─sh,25544 -c test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
              └─sh,25545 -c test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
                  └─run-parts,25546 --report /etc/cron.weekly
                      └─upgrade-system,26532 /etc/cron.weekly/upgrade-system
                          └─upgrade-system,26533 /usr/sbin/upgrade-system
                              └─apt-get,26546 -q -y -o DPkg::Options::=--force-confdef -u -fyu dist-upgrade
                                  └─dpkg,27392 --force-confdef --status-fd 27 --configure grub-pc grub manpages
                                      └─frontend,27393 -w /usr/share/debconf/frontend /var/lib/dpkg/info/grub-pc.postinst configure 1.98+20100804-8
                                          └─grub-pc.postins,27403 /var/lib/dpkg/info/grub-pc.postinst configure 1.98+20100804-8
                                              └─grub-mkconfig,29123 /usr/sbin/grub-mkconfig -o /boot/grub/grub.cfg
                                                  └─30_os-prober,29436 /etc/grub.d/30_os-prober
                                                      └─30_os-prober,29452 /etc/grub.d/30_os-prober
                                                          ├─os-prober,29453 /usr/bin/os-prober
                                                          │ └─50mounted-tests,30038 /usr/lib/os-probes/50mounted-tests /dev/mapper/md5vg-usr
                                                          │ └─mount,15757 -o ro -t ext3 /dev/mapper/md5vg-usr /var/lib/os-prober/mount
                                                          ├─paste,29455 -s -d
                                                          └─tr,29454 ^