uclibc can be configured without backtrace support, so check for it.

configure.sh

@@ -196,6 +196,7 @@ check_header sound/compress_offload.h USE_SNDDRV_COMPRESS_OFFLOAD
 check_header linux/kvm.h USE_KVM
 check_header linux/seccomp.h USE_SECCOMP
 check_header linux/vhost.h USE_VHOST
+check_header execinfo.h USE_BACKTRACE
 
 rm -f "$TMP" "$TMP.log" "$TMP.c"
 

debug.c

@@ -2,11 +2,14 @@
  * Various routines useful for debugging.
  */
 
+#include "config.h"
+
+#ifdef USE_BACKTRACE
 #include <execinfo.h>
+#endif
 #include <stdio.h>
 #include <stdarg.h>
 #include "child.h"
-#include "config.h"
 #include "debug.h"
 #include "log.h"
 #include "params.h"
@@ -18,6 +21,7 @@
 
 void show_backtrace(void)
 {
+#ifdef USE_BACKTRACE
 	unsigned int j, nptrs;
 	void *buffer[BACKTRACE_SIZE];
 	char **strings;
@@ -38,6 +42,7 @@ void show_backtrace(void)
 	free(strings);
 out:
 	set_dontkillme(getpid(), TRUE);
+#endif
 }
 
 void __BUG(const char *bugtxt, const char *filename, const char *funcname, unsigned int lineno)