# Node ID b24b1a3717f2a76299b43b9cc30e352cb6fa51ba
# Parent  535215e0f0758e3e8bf9520335c36910f8b4551d
diff --git a/tests/tests.py b/tests/tests.py
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -174,6 +174,11 @@
     _add_format_args(parser)
 
 def _run_tests(args):
+    if not os.path.isfile(args.gem5) or not os.access(args.gem5, os.X_OK):
+        print >> sys.stderr,
+            "gem5 binary '%s' not an executable file" % args.gem5
+        sys.exit(2)
+
     formatter = _create_formatter(args)
 
     out_base = os.path.abspath(args.directory)