grep -rhP '\buse\b' * | \
perl -E 'say $_ =~ /\buse\s+([\w:]+)/ for <>;' | \
sort | \
uniq | \
while read packname;
do
   perldoc -l $packname 2>&-;
done | \
grep -v '.pod$' | \
while read packfile;
do
   echo -n $packfile ' -> ';
   grep -P '\$([\w:]){0,}VERSION\b\s+=\s{0,}[[:punct:]]{0,1}\d' $packfile;
done