ERROR: transport error 202: gethostbyname: unknown host ERROR: JDWP Transport dt_socket failed to initialize, TRANSPORT_INIT(510) JDWP exit error AGENT_ERROR_TRANSPO
I had exactly the same issue (on OSX), in my case the line in /etc/hosts was commented out:
127.0.0.1 localhost
It's explained in Eclipse Wiki: https://wiki.eclipse.org/Debug/FAQ#I_can_run_a_program_but_not_debug_it.3F.3F.3F