Index: generic/nsfError.c
===================================================================
diff -u -N -rce2d2c1c7d116762e09e8bc047491eb4c3db4808 -r1c169da7a235853390dc8814cec00398048dbeda
--- generic/nsfError.c	(.../nsfError.c)	(revision ce2d2c1c7d116762e09e8bc047491eb4c3db4808)
+++ generic/nsfError.c	(.../nsfError.c)	(revision 1c169da7a235853390dc8814cec00398048dbeda)
@@ -70,7 +70,7 @@
    * estimation, however. Also, for MS VC runtimes, we use the vendor-specific
    * _vscprintf() 
    */
-#ifdef _WIN32
+#if defined(_WIN32) && defined(_MSC_VER)
   failure = (result == -1 && errno == ERANGE);
 #else
   assert(result > -1);
@@ -79,7 +79,7 @@
 
   if (failure) {
     int addedStringLength;
-#ifdef _WIN32
+#if defined(_WIN32) && defined(_MSC_VER)   
     /* Compute the required size of the Tcl_DString */
     va_copy(vargsCopy, vargs);
     addedStringLength = _vscprintf(fmt, vargsCopy);