diff --git a/lldb/packages/Python/lldbsuite/test/dotest.py b/lldb/packages/Python/lldbsuite/test/dotest.py
--- a/lldb/packages/Python/lldbsuite/test/dotest.py
+++ b/lldb/packages/Python/lldbsuite/test/dotest.py
@@ -1039,6 +1039,10 @@
             (configuration.suite.countTestCases(),
              configuration.suite.countTestCases() != 1 and "s" or ""))
 
+    if configuration.suite.countTestCases() == 0:
+        print("error: did not discover any tests.")
+        exitTestSuite(1)
+
     # Invoke the test runner.
     if configuration.count == 1:
         result = unittest2.TextTestRunner(