Pharo FFI Error: "Could not coerce arguments"

Hello

When trying out the FFI-Unix-Examples (X11Display class >
#coloredEllipses or #coloredRectangels) I get the error: "Could not
coerce arguments". When trying x11Draw I get a MNU: receiver of
"display" is nil.

I am running Pharo2 on NetBSD 6.1. I know this is not the usual
Linux/MacOS/Windows, but everything else works fine, except for FFI. I
am thinking I am quite close to getting FFI to work, just the from of
the pragma that is wrong. Any help is much appreciated.