You can valgrind all the tests by running:

  % make valgrind

To valgrind an individual test binary (wocky-porter-test, say), run:

  % make wocky-porter-test.valgrind

If you want to pass arguments to the tests when valgrinding (perhaps you've
narrowed the leaky test down to one test case, /xmpp-porter/cancel-iq-closing
say), run:

  % make wocky-porter-test.valgrind \
         TEST_ARGS='-p /xmpp-porter/cancel-iq-closing'