Make it compile
diff --git a/default.nix b/default.nix
index 6cb0bac..0ce641b 100644
--- a/default.nix
+++ b/default.nix
@@ -11,6 +11,7 @@
     gprbuild
     spark2014
     z3
+    cppcheck
   ];
 
   gprFile = "default.gpr";