media/libcubeb/src/cubeb_alsa.c:613:9: error: implicitly declaring library function 'snprintf' with type 'int (char *, unsigned int, const char *, ...)' [-Werror,-Wimplicit-function-declaration]
    r = snprintf(node_name, sizeof(node_name), "pcm.%s", string);
        ^
media/libcubeb/src/cubeb_alsa.c:613:9: note: include the header <stdio.h> or explicitly provide a declaration for 'snprintf'
media/libcubeb/src/cubeb_alsa.c:1168:3: error: implicitly declaring library function 'alloca' with type 'void *(unsigned int)' [-Werror,-Wimplicit-function-declaration]
  snd_pcm_hw_params_alloca(&hw_params);
  ^
/usr/local/include/alsa/pcm.h:737:39: note: expanded from macro 'snd_pcm_hw_params_alloca'
#define snd_pcm_hw_params_alloca(ptr) __snd_alloca(ptr, snd_pcm_hw_params)
                                      ^
/usr/local/include/alsa/global.h:106:57: note: expanded from macro '__snd_alloca'
#define __snd_alloca(ptr,type) do { *ptr = (type##_t *) alloca(type##_sizeof()); memset(*ptr, 0, type##_sizeof()); } while (0)
                                                        ^
media/libcubeb/src/cubeb_alsa.c:1168:3: note: include the header <stdlib.h> or explicitly provide a declaration for 'alloca'
/usr/local/include/alsa/pcm.h:737:39: note: expanded from macro 'snd_pcm_hw_params_alloca'
#define snd_pcm_hw_params_alloca(ptr) __snd_alloca(ptr, snd_pcm_hw_params)
                                      ^
/usr/local/include/alsa/global.h:106:57: note: expanded from macro '__snd_alloca'
#define __snd_alloca(ptr,type) do { *ptr = (type##_t *) alloca(type##_sizeof()); memset(*ptr, 0, type##_sizeof()); } while (0)
                                                        ^
2 errors generated.

--- media/libcubeb/src/cubeb_alsa.c.orig	2021-08-31 14:26:24.530548000 +0200
+++ media/libcubeb/src/cubeb_alsa.c	2021-08-31 14:26:43.081470000 +0200
@@ -5,9 +5,7 @@
  * accompanying file LICENSE for details.
  */
 #undef NDEBUG
-#define _DEFAULT_SOURCE
-#define _BSD_SOURCE
-#define _XOPEN_SOURCE 500
+#define _GNU_SOURCE 1
 #include "cubeb-internal.h"
 #include "cubeb/cubeb.h"
 #include <alsa/asoundlib.h>