split out upstart-sysv

Dimitri and I discussed that this morning. It's really hairy to move a lot of conffiles from one package to another. We resolved to this:

 * Split out upstart-sysv with just /sbin/init, reboot, etc. (similar to systemd-sysv)
 * Keep the config files in upstart
 * change init to depend on systemd-sysv | upstart-sysv
 * change systemd to conflict to upstart-sysv instead
 * make upstart depends: init, to ensure that we never lose an init system during upgrade

just copying description from my duplicate bug as i think its probably / possibly useful

As seen in the failed systemd adt test at [1], installing 'upstart-bin' and then booting a system with 'init=/sbin/upstart' does not result in a fully functional system. The problem is that there are many upstart jobs provided by 'upstart' package that are essential to Ubuntu system boot.

To recreate the problem, just launch a cloud-instance, or fresh install with systemd, then:
  sudo apt-get install upstart-bin
  set /etc/default/grub up appropriately and run 'update-grub' (adding 'init=/sbin/upstart to GRUB_CMDLINE_LINUX_DEFAULT). Alternatively, you can just edit /bo
ot/grub/grub.cfg directly.
  reboot

System will not completely come up.

Installation of 'upstart' package *does* provide working boot, but conflicts and forces uninstallation of systemd-sysv, which is not desireable.

For reference, there is discussion in ubuntu-release between infinity, didrocks, smoser and cjwatson on 2015-03-18 [2] and 2015-03-19 [3].

--
[1] https://jenkins.qa.ubuntu.com/job/vivid-adt-systemd/ARCH=amd64,label=adt/121/consoleFull
[2] http://irclogs.ubuntu.com/2015/03/18/%23ubuntu-release.html
[3] http://irclogs.ubuntu.com/2015/03/19/%23ubuntu-release.html

This bug was fixed in the package upstart - 1.13.2-0ubuntu10

---------------
upstart (1.13.2-0ubuntu10) vivid; urgency=medium

  * Add upstart-sysv to mirror systemd-sysv behavior if upstart is chosen
    as the default init daemon: (LP: #1422681)
    - this fixes upstart not starting only with upstart-bin binary due to
      missing jobs.
    - upstart now contains upstart-bin binaries.
    - upstart-bin is a transitional package. Can be deleted in vivid+1.
    - removed some deprecated transition path for both debian and ubuntu.
    - ensure grub is updated when upstart-sysv is installed.
    - always get alternatives init and right default grub entries.
 -- Didier Roche <email address hidden> Mon, 23 Mar 2015 09:51:12 +0100

This bug was fixed in the package systemd - 219-4ubuntu9

---------------
systemd (219-4ubuntu9) vivid; urgency=medium

  * debian/control:
    - systemd-sysv now conflicts with upstart-sysv, not upstart itself
      which contains upstart binaries. (LP: #1422681)
  * debian/test/*:
    - re-enable upstart boot test and switch to upstart instead of
      upstart-bin
  * debian/systemd-sysv.postinst:
    - fix syntax for better portability
 -- Didier Roche <email address hidden> Mon, 23 Mar 2015 10:21:34 +0100

This bug was fixed in the package init-system-helpers - 1.22ubuntu5

---------------
init-system-helpers (1.22ubuntu5) vivid; urgency=medium

  * Depend on upstart-sysv instead of upstart (LP: #1422681)
 -- Didier Roche <email address hidden> Mon, 23 Mar 2015 10:44:07 +0100

This bug was fixed in the package autopkgtest - 3.12ubuntu1

---------------
autopkgtest (3.12ubuntu1) vivid; urgency=medium

  * use the upstart path to start an upstart ubuntu touch session
    (LP: #1422681)
 -- Didier Roche <email address hidden> Mon, 23 Mar 2015 18:42:25 +0100

https://launchpad.net/ubuntu/+source/ubuntu-touch-meta/1.217