Just in case it can help somebody: I think the message about unlinking the output file is misleading and it never gets created in the first place due to EACCES for a file in /var/tmp shown by strac'ing cups. At least this was the case for me, and I think is also the case in the similar Debian bug report (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=931363).
The solution is to either chmod /var/tmp to 777 or create some other directory (I used /var/tmp/cups-pdf) and give everybody the right to write in it.
Just in case it can help somebody: I think the message about unlinking the output file is misleading and it never gets created in the first place due to EACCES for a file in /var/tmp shown by strac'ing cups. At least this was the case for me, and I think is also the case in the similar Debian bug report (https:/ /bugs.debian. org/cgi- bin/bugreport. cgi?bug= 931363).
The solution is to either chmod /var/tmp to 777 or create some other directory (I used /var/tmp/cups-pdf) and give everybody the right to write in it.