Octave: error() must be called with an argument

Examples/test-suite/octave/inout_runme.m

@@ -2,26 +2,26 @@ inout
 
 a = inout.AddOne1(1);
 if (a != 2)
-  error
+  error("failed");
 endif
 
 a = inout.AddOne3(1,1,1);
 if (a != [2,2,2])
-  error
+  error("failed");
 endif
 
 a = inout.AddOne1p((1,1));
 if (a != (2,2))
-  error
+  error("failed");
 endif
 
 a = inout.AddOne2p((1,1),1);
 if (a != [(2,2),2])
-  error
+  error("failed");
 endif
 
 a = inout.AddOne3p(1,(1,1),1);
 if (a != [2,(2,2),2])
-  error
+  error("failed");
 endif