Ok, getting further: the problem was with this bit of shell:If the list of files downloaded doesn't *exactly* match the list in the md5sum file it fails. Since jessie appeared this obviously failed. I've rejigged the code to not have this problem anymore and set it running. I'll check in the morning to see how it progressed.
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for distribution in $DISTS squeeze md5sum timestamp timestamp.gpg
do
rm -f $distribution
wget -q -m -nd http://ftp-master.debian.org/i18n/$distribution || \
echo "failed to wget http://ftp-master.debian.org/i18n/$distribution"
done
md5sum --check --quiet md5sum
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