The feature is available using the --keep_src_list option. Closing this 
bugreport therefor, if you think it's not resolved yet for you please feel free 
to reopen it. Thanks.

regards,
-mika-

hi,

The current implementation of grml-debootstrap allows only one foreign
repo from grml. However, there are cases that multiple apt repos are
desired. For eg, I need the debian-multimedia and security.debian.org
as well.

So far the new patch allows user to use their own apt/sources.list,
but the problem is the gpg keys. So I proposed the following, which is
from  lh_chroot_sources:

store use's own apt sources entries one by one in

chroot_sources/*.chroot

store their corresponding gpg keys as

chroot_sources/*.chroot.gpg

then,

		# Check local sources.list
		if Find_files config/chroot_sources/*.chroot
		then
			echo "" >> chroot/etc/apt/sources.list
			echo "# Custom repositories" >> chroot/etc/apt/sources.list

			for FILE in config/chroot_sources/*.chroot
			do
				cat ${FILE} | grep -v "^##" >> chroot/etc/apt/sources.list
			done
		fi

. . .

			if Find_files config/chroot_sources/*.chroot.gpg
			then
				for FILE in config/chroot_sources/*.chroot.gpg
				do
					cp ${FILE} chroot/root
					Chroot "apt-key add /root/$(basename ${FILE})"
					rm -f chroot/root/$(basename ${FILE})
				done
			fi

[shamelessly ripped from /usr/bin/lh_chroot_sources]

Mika, this is kind of major overhauls that I don't feel comfortable
messing with (at my early stage of grml-debootstrap hacking). Would
you like to take care of it at your earliest convenient?

thanks