do not use Executor if only one process was requested
This will make verbose output nicer, since it will not interleave the test
stdout/stderr and the test results.
@@ -893,7 +893,7 @@ Timeout: %4d
visible_name = self.get_pretty_suite(test)
single_test = self.get_test_runner(test)
- if not test.is_parallel or single_test.options.gdb:
+ if not test.is_parallel or self.options.num_processes == 1 or single_test.options.gdb:
self.drain_futures(futures)
futures = []
res = single_test.run()
