Fail if simulator exits early.

diff --git a/debug/testlib.py b/debug/testlib.py
index b5bd992234cd2252a30d2018076d71614d1459a1..3d08e9b33e172388433950d74f5de40cbb27d2fb 100644 (file)
--- a/debug/testlib.py
+++ b/debug/testlib.py
@@ -132,6 +132,12 @@ class VcsSim(object):
                 stdout=logfile, stderr=logfile)
         done = False
         while not done:
+            # Fail if VCS exits early
+            exit_code = self.process.poll()
+            if exit_code is not None:
+                raise RuntimeError('VCS simulator exited early with status %d'
+                                   % exit_code)
+
             line = listenfile.readline()
             if not line:
                 time.sleep(1)