Comment 1 for bug 129785

This failure is due to the substvars in debian/rules which is based on the mozilla-thunderbird version being probed by this rules assignment:

TBIRD_VERSION = $(shell dpkg -s mozilla-thunderbird-dev|grep ^Version|cut -d\ -f2|cut -d- -f1 | cut -d. -f-3)

Note that the Build-Dependency in debian/control is on mozilla-thunderbird-dev.
mozilla-thunderbird was a required dependency of mozilla-thunderbird-dev until feisty.
On gutsy, mozilla-thunderbird is NOT a required dependency of mozilla-thunderbird-dev, therefore the above assignment returns a null string (as seen in the build log).

This can be solved by:

1) Making mozilla-thunderbird a required dependency of mozilla-thunderbird-dev also for gutsy or
2) Making mozilla-thunderbird as a Build-Dependancy in debian/control or
3) Changing the above assignment so that it is based on mozilla-thunderbird-dev

I attach a patch hereabove based on solution 3).

The package builds without any problem, see snippet from build log:

echo -n "tbird:Depends=mozilla-thunderbird (>= 2.0.0)" \
           >> debian/thunderbird-quickfile.substvars
echo ", mozilla-thunderbird (<< 2.0.0.99)" \
           >> debian/thunderbird-quickfile.substvars

Thanks.