There are files that tazlito has to get from the livecd or iso image.
Tazlito wants /boot/isolinux/isolinux.bin
Put the slitaz livecd in cdrom drive

tazlito gen-distro --cdrom

or use slitaz-3.0.iso

tazlito gen-distro --iso=path to slitaz.iso

gen-distro

The Generate Distribution command can generate the distro-tree and an ISO image via a list of packages. To function, this command needs a list of packages, a directory containing all the (.tazpkg) packages on the list, and a directory to generate the distribution. The list of packages can be extracted from a flavor by the 'get-flavor' command. If one uses the LiveCD, the options --cdrom and --iso= permit the regeneration of packages that place files in /boot without being obliged to download them and recovers the additional files of the LiveCD. The path to the various directories are configured in the configuration file and packages can be downloaded from the SliTaz mirrors or generated by Tazwok.

Interesting that option Mojo ,

Wasn't mentionned among the tazlito command ..

But I suppose that the packages listed in the distro-packages.list ,but not figuring in the LiveCD/iso, must be downloaded anyway .

Otherwise, does it make sense to use packages from an Iso if the goal is to create exactly the same iso ? :D

But what can I do for my problem on top here ? I've found a funny solution, there was no iso , but a rootfs.gz , so I've just downloaded the base iso and replace the rootfs.gz with mine one