What does cc -v say? The same thing? What does echo $CC say?
The other thing is, you're using an old version of NVchooser.sh. This script is changed on every driver release -- you have to use the one that you download from the same page as the driver you're going to install.
That said, you probably want to get the NVchooser from either the 3123 download page or the 4191 download page, and run it. You may not even need to install from source.