Index: b/boehm-gc/include/gc.h
===================================================================
--- a/boehm-gc/include/gc.h
+++ b/boehm-gc/include/gc.h
@@ -503,7 +503,7 @@
 #if defined(__linux__) || defined(__GLIBC__)
 # include <features.h>
 # if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 || __GLIBC__ > 2) \
-     && !defined(__ia64__)
+     && !defined(__ia64__) && !defined(__UCLIBC__)
 #   ifndef GC_HAVE_BUILTIN_BACKTRACE
 #     define GC_HAVE_BUILTIN_BACKTRACE
 #   endif