$NetBSD: patch-gr-audio_lib_alsa_alsa__impl_h,v 1.4 2021/04/07 16:14:07 tnn Exp $

gnuradio-3.7.2.1/gr-audio/lib/alsa/alsa_source.cc:477:23: error: 'ESTRPIPE' was not declared in this scope
See also
https://mail-index.netbsd.org/pkgsrc-wip-discuss/2013/10/27/msg002529.html

--- gr-audio/lib/alsa/alsa_impl.h.orig	2021-03-22 22:37:12.000000000 +0000
+++ gr-audio/lib/alsa/alsa_impl.h
@@ -14,6 +14,10 @@
 #include <alsa/asoundlib.h>
 #include <cstdio>
 
+#ifndef ESTRPIPE
+#define ESTRPIPE EPIPE
+#endif
+
 void gri_alsa_dump_hw_params(snd_pcm_t* pcm, snd_pcm_hw_params_t* hwparams, FILE* fp);
 
 bool gri_alsa_pick_acceptable_format(snd_pcm_t* pcm,