Comment 7 for bug 104038

Let me start with that I'm no expert on the installation system, but here's what I've learnt so far:

$dpkg -S tty1
system-services: /etc/event.d/tty1

$dpkg -L system-services
[..]
/usr/lib/upstart/migrate-inittab.pl
[..]

$cat /var/lib/dpkg/info/system-services.postinst
{confirms that /usr/lib/upstart/migrate-inittab.pl does the work}

That means to my mind that the error is very likely happening within migrate-inittab.pl

(Of course it may well be that this was obvious to all involved.)

I'll do some Perl RTFM-ing and see what I learn.