GNAT version does not support Ada-2012 standard. Would be good to have the same version of gcc as the system base (currently 4.6.2) or 4.7.0 Why is Ada not supported by a use flag like fortran?
need gnat-gcc >= 4.6 for SPARK support.
+1
I just commited 4.6.4 (better late than never ;) Have at it...