M Makefile → Makefile

@@ -20,6 +20,12 @@ HAVE_ALSA := $(shell echo '\#include <alsa/asoundlib.h>' | $(CC) -E - >/dev/null 2>&1 && echo 1)
     ifeq ($(HAVE_ALSA),1)
         LDFLAGS += -lasound
     endif
+	# Fallback to libossaudio
+else ifeq ($(HAVE_OSSAUDIO),1)
+    LDLIBS += -lossaudio
+else
+	# No audio backend (beeper will throw an error)
+    CFLAGS += -DXYW_NO_AUDIO_BACKEND
 endif
 
 .PHONY: clean test

M devices/beeper.c → devices/beeper.c

@@ -82,7 +82,17 @@ *out_frames = frames;
     return buf;
 }
 
-#if defined(_WIN32)
+#if defined(XYW_NO_AUDIO_BACKEND)
+
+static void beep_play_tone(double frequency_hz, unsigned long duration_ms, double volume, xyw_byte *error)
+{
+    (void)frequency_hz;
+    (void)duration_ms;
+    (void)volume;
+    *error = BEEPER_ERROR_DEVICE;
+}
+
+#elif defined(_WIN32)
 
 #include <windows.h>
 #include <mmsystem.h>