Issue 5619: Pass MS CRT debug flags into subprocesses
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index d0c5b2b..b3866ce 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -1634,6 +1634,8 @@
 Py_FatalError(const char *msg)
 {
 	fprintf(stderr, "Fatal Python error: %s\n", msg);
+	fflush(stderr); /* it helps in Windows debug build */
+
 #ifdef MS_WINDOWS
 	{
 		size_t len = strlen(msg);