The samba-common.postinst maintainer script is sourcing debconf's confmodule in the middle of the script. Moving this line to the top of the .postinst script fixes the error and samba-common now installs properly.
The samba-common. postinst maintainer script is sourcing debconf's confmodule in the middle of the script. Moving this line to the top of the .postinst script fixes the error and samba-common now installs properly.