According to 'apt-file search mkiso' (or http://packages.ubuntu.com for that matter) no /usr/bin/mkiso file exists in any edgy package in the repositories. As such, it seems that this script is not part of ubuntu. If you acquired/installed it from somewhere else please file a bug with the author of the script directly.
Feel free to reopen the bug in case I overlooked something. ** Changed in: Ubuntu Status: Unconfirmed => Rejected -- mkiso returns an error always https://launchpad.net/bugs/72945 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs