Mockito is currently self-attaching to enable the inline-mock-maker. This will no longer work in future releases of the JDK. Please add Mockito as an agent to your build what is described in Mockito's documentation: https://javadoc.io/doc/org.mockito/mockito-core/latest/org/mockito/Mockito.html#0.3 WARNING: A Java agent has been loaded dynamically (/tmp/r/net/bytebuddy/byte-buddy-agent/1.15.4/byte-buddy-agent-1.15.4.jar) WARNING: If a serviceability tool is in use, please run with -XX:+EnableDynamicAgentLoading to hide this warning WARNING: If a serviceability tool is not in use, please run with -Djdk.instrument.traceUsage for more information WARNING: Dynamic loading of agents will be disallowed by default in a future release NETCONF ID | NETCONF IP | NETCONF Port | Status -----------+---------------+--------------+------------- | [192.168.1.1] | [7777] | [connecting] NETCONF ID | NETCONF IP | NETCONF Port | Status | Available Capabilities -----------+-------------+--------------+------------+----------------------- device | 192.168.1.1 | 7777 | connecting | cap1 | | | | cap2 | | | | cap3 NETCONF ID | NETCONF IP | NETCONF Port | Status | Available Capabilities -----------+-------------+--------------+------------+----------------------- device | 192.168.1.1 | 7777 | connecting | cap1 | | | | cap2 | | | | cap3