Revised on 2015.09.17

This issue has been created following the concern of changes in recent Ubuntu-based ISO images, especially Ubuntu Mini Remix (UMR) ISO images.

Since 13.10 release, it has been reported on this Ubuntu Launchpad thread that the livecd-root bash script had been removed (probably from ISO image content or default packages).

The original custom shell script in livecd-rootfs [has been moved] to the newer live-build system from Debian (formerly called live-helper).. This only affects Oneiric and later releases. More details in this debian-live mailing list back in 2011 and this stable manual.

Following this change, UMR faced difficulties to build the base of Ubuntu squashfs without the script. Its recent ISO image is likely built using ubuntu-defaults-builders to install just the "base" flavour (minimal + standard metapackages), cited from same thread above.

The current UMR releases are somewhat compatible and usable by Customizer, but it is claimed to have different ISO structure and some Live CD features may not work.

Besides this, if anyone can suggest other method to build Ubuntu base from scratch (plus can confirm that it is compatible with Customizer), that is also welcomed. I know there is Ubuntu community page for this, but may not work well for recent Ubuntu releases.