Source: https://github.com/macports/macports-ports/blob/master/audio/aften/files/patch-fix-apple-silicon.diff

--- a/libaften/cpu_caps.h
+++ b/libaften/cpu_caps.h
@@ -26,6 +26,7 @@
 #include "ppc_cpu_caps.h"
 #else
 static inline void cpu_caps_detect(void){}
+static inline void apply_simd_restrictions(AftenSimdInstructions *simd_instructions){}
 #endif

 #endif /* CPU_CAPS_H */