debian/configure

Do these help?

kkirwan@kkirwan-E627a /etc/apt $ ls -l
total 52
drwxr-xr-x 2 root root  4096 Oct 22 01:29 apt.conf.d
drwxr-xr-x 2 root root  4096 Oct 18 18:51 preferences.d
-rw-r--r-- 1 root root    90 Oct 17 17:17 sources.list
drwxr-xr-x 2 root root  4096 Oct 22 16:04 sources.list.d
-rw-r--r-- 1 root root 15221 Oct 22 16:02 trusted.gpg
-rw-r--r-- 1 root root 14863 Oct 22 01:12 trusted.gpg~
drwxr-xr-x 2 root root  4096 Apr 14  2016 trusted.gpg.d
kkirwan@kkirwan-E627a /etc/apt $ cat sources.list
#deb cdrom:[Linux Mint 18 _Sarah_ - Release amd64 20160628]/ xenial contrib main non-free
kkirwan@kkirwan-E627a /etc/apt $ 

kkirwan@kkirwan-E627a /etc/apt/sources.list.d $ ls -l
total 20
-rw-r--r-- 1 root root 168 Oct 22 16:03 freecad-maintainers-freecad-daily-xenial.list
-rw-r--r-- 1 root root 174 Oct 22 16:03 freecad-maintainers-freecad-stable-xenial.list
-rw-r--r-- 1 root root 138 Oct 22 16:04 js-reynaud-kicad-4-xenial.list
-rw-r--r-- 1 root root 146 Oct 22 16:02 js-reynaud-ppa-kicad-xenial.list
-rw-r--r-- 1 root root 561 Jun 28 07:39 official-package-repositories.list
kkirwan@kkirwan-E627a /etc/apt/sources.list.d $ cat freecad-maintainers-freecad-daily-xenial.list 
deb http://ppa.launchpad.net/freecad-maintainers/freecad-daily/ubuntu xenial main
deb-src http://ppa.launchpad.net/freecad-maintainers/freecad-daily/ubuntu xenial main
kkirwan@kkirwan-E627a /etc/apt/sources.list.d $ 

Thanks for looking!