update error message

JAi-SATHVIK · JAi-SATHVIK · commit e9814be2068e · 2026-03-12T23:46:47.000+05:30
diff --git a/src/math/stdlib_math_diff.fypp b/src/math/stdlib_math_diff.fypp
@@ -97,7 +97,7 @@ contains
             case (2)
                 allocate(y(size(x, 1), 0))
             case default
-                error stop "diff_2: invalid dimension (dim_ must be 1 or 2)"
+                error stop "diff_2: internal error: invalid dimension (dim_ must be 1 or 2)"
             end select
             return
         end if
