Indeed. Even when you see the hidden unicode it's still not obvious what's going on.

The "salmon" string is mostly unicode TAG characters[1] which contains the printed string followed by 2 En Quad[2], which not so obviously has the effect that `putchar` returns 0 when given as it's argument. Then the defines aren't what they seem, and the body of main is never executed because it's surrounded by a while loop where the condition is 0 (due to putchar() with en quad).

[1]:https://unicodeplus.com/block/E0000

[2]:https://unicodeplus.com/U+2000