Hi Ryan,
I don't think there's anything wrong with hardcoding invoke-rc.d in
d/rules, not more so than hardcoding it in a maintainer script.
Ubuntu bug #1308571 predated the change to use invoke-rc.d in Debian;
the failure in this case was due to the previous behavior of Ganeti
calling the initscript directly, and this is clearly mentioned in that
report.
Since we do not provide an upstart job for ganeti, invoke-rc.d should
work as expected, but can you please verify that 2.11.2 works with the
latest Ubuntu?
Regards,
Apollon