bitcoin-0.12.0/bin/bitcoin-qt -testnet -server -zmqpubhashblock=127.0.0.1

It's very unclear what the format of "address" should be, so I just tried a bunch. This is 0.12rc3.

The above causes an infinite loop at startup. "Verifying wallet" and when quitting the scary window "Do not shut down the computer until this window disappears." Luckily nothing is corrupted by just killing it and trying again.

Missing .// in the address causes assertion + core dump. At least less scary/confusing than above.

bitcoin-0.12.0/bin/bitcoin-qt -testnet -server -debug=1 -zmqpubhashblock=tcp://127.0.0.1:28332 -zmqpuawtx=tcp://127.0.0.1:28332 -zmqpubhashtx=tcp://127.0.0.1:28332 -zmqpubrawblock=tcp:127.0.0.1:28332
bitcoin-qt: zmq/zmqpublishnotifier.cpp:92: virtual void CZMQAbstractPublishNotifier::Shutdown(): Assertion `psocket' failed.
Aborted (core dumped)