View source for VisIt:compile hack hack

If you want to use an existing installation of the 3rd party software 
(note that that in some cases VisIt requires older versions) you can 
force this with the following hack (uses Python as an example):

From the directory you run build_visit from, run the
command:

   mkdir -p visit/python/2.5/linux-x86_64_gcc-4.1.2 (last bit is architecture/compiler dependant)

This will cause build_visit to think python is already installed,
skipping the compile/install of it.  However, after build_visit
completes, you'll have to change your `host`.conf.  Simply change the

   PYDIR=/some/long/directory/name

line to:

   PYDIR=/usr

This will cause VisIt to use your system's python.