BTW, apparently Options is deprecated and one is supposed to use
Variables instead. There is a ListVariable which might be able to do
the right thing (allow a list of validated directories), but I can't
really tell from the documentation as it is exceedingly minimal.
No, ListVariable is the equivalent of ListOption, as far as I can tell,
and that allows you to pick none, one or more values from a list.
Variables also are not present in 0.96 or older scons releases, so we
can't use those until we require a newer version of scons. (This won't
be the newly-released 0.98 because 0.98.3 has some C++ configure test
regressions, although 0.98.2 seems OK.)
Ben
--
http://salilab.org/~ben/
"It is a capital mistake to theorize before one has data."
- Sir Arthur Conan Doyle