# check for repetitions of deps
depdir="$(get_temp tg-depdir -d)" ||
die "Can't check for multiple occurrences of deps"
-cat_file "(i):.topdeps" |
+cat_file "$head_:.topdeps" -i |
while read dep; do
[ ! -d "$depdir/$dep" ] ||
die "Multiple occurrences of the same dep: $dep"