IMHO chroot of cook-undigest is not sane, and this is the reason why there can not cook most of the packages.
In confirmation of my words, take a look at the cooking log of the navit package. Unfortunately, at the moment I can not reach cooker site. But I remember that I saw a strange repeating lines and strange headers (.h) which do not belong to any package (according pkgs.slitaz.org) and which led to the package cooking error. Please, clean/sane/recreate chroot for cook-undigest.
