tests: Exit serial test runner gracefully when no tests are specified

This avoids the test failing when invoking make with `TESTS=xxx` to
limit which tests are run.

Change-Id: I89c7096a64acc68114d4ca2d0042a219c57ad23a
Signed-off-by: Kienan Stewart <kstewart@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/tests/regression/tests.serial b/tests/regression/tests.serial
index a99352fe1c523f5b9dab0bf66d575a375387351a..c936309f6ed46af3858ca48b4878ad6c53c0920d 100755 (executable)
--- a/tests/regression/tests.serial
+++ b/tests/regression/tests.serial
@@ -191,5 +191,11 @@ if __name__ == "__main__":
 
     logging.info("Serial tests received %d tests", len(tests))
     logging.debug("Serial tests: {}".format(tests))
+
+    if len(tests) == 0:
+        tap = lttngtest.TapGenerator(1)
+        tap.skip("No tests specified by the environment")
+        sys.exit(0)
+
     if not run_tests(tests):
         sys.exit(1)