Comment 3 for bug 250400

It fails in an automatic upgrade/installation environment because the PATH variables are different than if you're using a shell. /usr/sbin is not included if a cron runs the upgrade (or installation) - therefor the command "make-ssl-cert" fails to create the files (because the file is not executed) and then the "chmod" and "chgrp" fail because there is no file to modify and exit with code 1.
you could either change the PATH envorinment variable for cron OR adapt the script so it doesn't fail (should have absolute paths anyway!!!)

it's two times in the postinstallation script [line 32 and line 40]

if the path gets changed to an absolute one, everything works as expected (i tested this)

line 32 old:
make-ssl-cert generate-default-snakeoil --force-overwrite

line 32 new:
/usr/sbin/make-ssl-cert generate-default-snakeoil --force-overwrite

line 40 old:
make-ssl-cert generate-default-snakeoil

line 40 new:
/usr/sbin/make-ssl-cert generate-default-snakeoil

thats it ...! could be closed pretty easy and fast
also affects feisty version 1.0.13 --> same problem!
i haven't looked at the intrepid version of the postinst script, but i suspect the problem could be there too - worth a look ;)