progs/trivial: add fflushes for cygwin
diff --git a/progs/trivial/quadstrip-flat.c b/progs/trivial/quadstrip-flat.c
index 9011ee0..228c6c2 100644
--- a/progs/trivial/quadstrip-flat.c
+++ b/progs/trivial/quadstrip-flat.c
@@ -39,6 +39,7 @@
fprintf(stderr, "GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
fprintf(stderr, "GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
fprintf(stderr, "GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR));
+ fflush(stderr);
glClearColor(0.0, 0.0, 1.0, 0.0);
}