Index: include/__bsd_locale_fallbacks.h
===================================================================
--- include/__bsd_locale_fallbacks.h
+++ include/__bsd_locale_fallbacks.h
@@ -118,7 +118,26 @@
     va_list __va;
     va_start(__va, __format);
     __locale_raii __current( uselocale(__l), uselocale );
+#if _LIBCPP_HAS_NO_ASPRINTF
+    va_list __va2;
+    va_copy(__va2, __va);
+    int __res = vsnprintf(0, 0, __format, __va2);
+    va_end(__va2);
+    if(__res < 0)
+    {
+        va_end(__va);
+        return __res;
+    }
+    *__s = (char *)malloc(__res+1);
+    if(*__s == 0)
+    {
+        va_end(__va);
+        return -1;
+    }
+    vsnprintf(*__s, __res+1, __format, __va);
+#else
     int __res = vasprintf(__s, __format, __va);
+#endif
     va_end(__va);
     return __res;
 }
Index: include/__config
===================================================================
--- include/__config
+++ include/__config
@@ -871,6 +871,10 @@
 #endif
 #endif
 
+#if defined(_NEWLIB_VERSION)
+#define _LIBCPP_HAS_NO_ASPRINTF 1
+#endif
+
 #ifdef __FreeBSD__
 #define _DECLARE_C99_LDBL_MATH 1
 #endif