Index: libcxx/trunk/include/__debug
===================================================================
--- libcxx/trunk/include/__debug
+++ libcxx/trunk/include/__debug
@@ -22,7 +22,7 @@
 #   include <cstdio>
 #   include <cstddef>
 #   ifndef _LIBCPP_ASSERT
-#      define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : (_VSTD::printf("%s\n", m), _VSTD::abort()))
+#      define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : (_VSTD::fprintf(stderr, "%s\n", m), _VSTD::abort()))
 #   endif
 #endif
 
Index: libcxx/trunk/src/exception.cpp
===================================================================
--- libcxx/trunk/src/exception.cpp
+++ libcxx/trunk/src/exception.cpp
@@ -90,14 +90,14 @@
 #endif  // _LIBCPP_NO_EXCEPTIONS
         (*get_terminate())();
         // handler should not return
-        printf("terminate_handler unexpectedly returned\n");
+        fprintf(stderr, "terminate_handler unexpectedly returned\n");
         ::abort();
 #ifndef _LIBCPP_NO_EXCEPTIONS
     }
     catch (...)
     {
         // handler should not throw exception
-        printf("terminate_handler unexpectedly threw an exception\n");
+        fprintf(stderr, "terminate_handler unexpectedly threw an exception\n");
         ::abort();
     }
 #endif  // _LIBCPP_NO_EXCEPTIONS
@@ -117,7 +117,7 @@
 #   else
 #       warning uncaught_exception not yet implemented
 #   endif
-    printf("uncaught_exception not yet implemented\n");
+    fprintf(stderr, "uncaught_exception not yet implemented\n");
     ::abort();
 #endif  // __APPLE__
 }
@@ -190,7 +190,7 @@
 #   else
 #       warning exception_ptr not yet implemented
 #   endif
-    printf("exception_ptr not yet implemented\n");
+    fprintf(stderr, "exception_ptr not yet implemented\n");
     ::abort();
 #endif
 }
@@ -209,7 +209,7 @@
 #   else
 #       warning exception_ptr not yet implemented
 #   endif
-    printf("exception_ptr not yet implemented\n");
+    fprintf(stderr, "exception_ptr not yet implemented\n");
     ::abort();
 #endif
 }
@@ -234,7 +234,7 @@
 #   else
 #       warning exception_ptr not yet implemented
 #   endif
-    printf("exception_ptr not yet implemented\n");
+    fprintf(stderr, "exception_ptr not yet implemented\n");
     ::abort();
 #endif
 }
@@ -278,7 +278,7 @@
 #   else
 #       warning exception_ptr not yet implemented
 #   endif
-    printf("exception_ptr not yet implemented\n");
+    fprintf(stderr, "exception_ptr not yet implemented\n");
     ::abort();
 #endif
 }
@@ -300,7 +300,7 @@
 #   else
 #       warning exception_ptr not yet implemented
 #   endif
-    printf("exception_ptr not yet implemented\n");
+    fprintf(stderr, "exception_ptr not yet implemented\n");
     ::abort();
 #endif
 }
Index: libcxx/trunk/src/string.cpp
===================================================================
--- libcxx/trunk/src/string.cpp
+++ libcxx/trunk/src/string.cpp
@@ -39,7 +39,7 @@
 #ifndef _LIBCPP_NO_EXCEPTIONS
     throw T( msg );
 #else
-    printf("%s\n", msg.c_str());
+    fprintf(stderr, "%s\n", msg.c_str());
     abort();
 #endif
 }