[GRASS5] What if I leave out an option at compile time?

[Michael Rensing]

If I compile GRASS without some optional feature (e.g. BLAS support), 
what happens?

Will the capabilities which depend on the feature be visible, but not work?

Or will the dependent capabilities not show up at all?

I tend to learn some software features by browsing, and if capabilities 
are only visible if support is included at compilation, I'll need to add 
all support options to be able to explore the full capabilities of GRASS.

Can anyone comment?
Michael