package clonezilla 3.10.11-3 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

Status changed to 'Confirmed' because the bug affects multiple users.

from the postinst script

case "$1" in
    configure)
 ln -sf /usr/share/drbl /opt/
 mkdir -p /opt/drbl/conf
 ln -sf /etc/drbl/drbl.conf /opt/drbl/conf/
    ;;

I assume swapping the lines to have mkdir before the first ln command will solve the problem of the script failing if the /opt directory does not exist.

Had the same issue... and was missing /opt.

Swapping the lines would also create /opt/drbl ... such that the ln command fails with "ln: /opt/drbl: cannot overwrite directory"

Adding "mkdir /opt" would solve it ... but it's supposed to exist on a normal system ... right?

You might be right, apparently I was misinterpreting the actions of the script.

Probably the correct solution would be to add
mkdir -p /opt
before the first ln statement.

This could also be wrapped in an if.

I doubt that you can guarantee that the /opt directory is existing on all Linux variants that might install that package from the provided .deb file. "opt" sounds a bit like "optional".

Error-tolerant scripts should be able to cope with such situation.