Don't use apt-cdrom; just copy the host sources.list.

debian/changelog

@@ -1,6 +1,7 @@
 calamares-settings-ubuntu (8) UNRELEASED; urgency=medium
 
   * Finish Danish translations.
+  * Don't use apt-cdrom; just copy the host sources.list.
 
  -- Simon Quigley <tsimonq2@ubuntu.com>  Fri, 13 Jul 2018 20:49:19 -0500
 

lubuntu/modules/shellprocess.conf

@@ -2,5 +2,5 @@ dontChroot: true
 timeout: 300
 script:
   - "cp /cdrom/casper/vmlinuz @@ROOT@@/boot/vmlinuz-$(uname -r)"
-  - "[ -d /sys/firmware/efi ] && chroot @@ROOT@@ apt-cdrom add && chroot @@ROOT@@ sed -e '/deb http/ s/^#*/#/' -i /etc/apt/sources.list && chroot @@ROOT@@ apt update && chroot @@ROOT@@ apt -y install grub-efi-amd64-bin && chroot @@ROOT@@ sed -i 's/#deb/deb/' /etc/apt/sources.list || exit 0"
+  - "[ -d /sys/firmware/efi ] && cp /etc/apt/sources.list @@ROOT@@/etc/apt/sources.list && chroot @@ROOT@@ sed -e '/deb http/ s/^#*/#/' -i /etc/apt/sources.list && chroot @@ROOT@@ apt update && chroot @@ROOT@@ apt -y install grub-efi-amd64-bin && chroot @@ROOT@@ sed -i 's/#deb/deb/' /etc/apt/sources.list && sed -i '/deb cdrom/d' @@ROOT@@/etc/apt/sources.list || exit 0"
   - "for i in `ls @@ROOT@@/home/`; do rm @@ROOT@@/home/$i/Desktop/calamares.desktop || exit 0; done"