HDFS-6693 introduced some debug message to debug why when TestPipelinesFailover fails. HDFS-9438 restricted the debug message to Linux/Mac/Solaris. However, the test would fail when printing debug message if "ifconfig" command is not available in certain environment.
This is not quite right. The test should not fail due to the debug message printing. We should catch any exception thrown from the code that prints debug message, and issue a warning message.
Suggest to make this change.