Under Debian/wheezy it fails out-of-the-box under sudo:
| sudo /usr/sbin/grml2iso -c ./source/templates -o grml64-sipwise-release_20130626.iso grml64-full_2013.02.iso
| Error: Could not find grml2usb executable. Is /usr/sbin missing in PATH?
because of:
| ENV_SUPATH PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
| ENV_PATH PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
in /etc/login.defs.