Index: trunk/ppSim/src/ppSimInsertStars.c
===================================================================
--- trunk/ppSim/src/ppSimInsertStars.c	(revision 35770)
+++ trunk/ppSim/src/ppSimInsertStars.c	(revision 36375)
@@ -78,4 +78,5 @@
 
     FILE *outfile = fopen (outname, "w");
+    psAssert (outfile, "cannot write output");
 
     float radius = -1.0;