There are several failure with reason
"Cannot invoke "String.equals(Object)" because "<local1>" is null"
which really caused by reading the command from debugee via socket.
Like:
" String command = pipe.readln();

        if (!command.equals(AbstractDebuggeeTest.COMMAND_READY)) {
            setSuccess(false);
            log.complain("TEST BUG: unknown debuggee's command: " + command);

            return false;
        }
"
The command is null when socket fails with EOFException which usually means that debugee has been crashed/exited or killed by timeout handler.

However, it is not clear from the error log. So
https://bugs.openjdk.org/browse/JDK-8310940 has different problems with the same NPE symptom.

The fix update error handling to avoid this problem.