build_visit downloads some libraries even if already built/installed.

[biagas]

Is your feature request related to a problem?

After a successful run of build_visit, and a cleanup of all thirdparty tarballs, if I run it again some libraries that are already installed still get downloaded:

adios2-2.10.0.rc1.tar.gz
glu-9.0.0.tar.gz
ilmbase-2.2.0.tar.gz
ospray-libs-3.0.0.tar.gz
vtk-m-v1.9.0.tar.gz

Describe the solution you'd like.

It would be nice if build_visit only downloaded libraries it needs, not ones already installed.