For example, mach mochitest testing/mochitest/tests/Harness_sanity runs 2 flavors of mochitest, one after the other. If I attempt to break out of the test run with ctrl-c during the first flavor, that run is aborted, but then the next flavor starts up. I find that annoying. I also think this behavior encourages people to hit ctrl-c repeatedly when they really want to break out of the test run, and I think that could result in orphaned servers.

0 INFO SimpleTest START 1 INFO TEST-START | testing/mochitest/tests/Harness_sanity/test_SimpletestGetTestFileURL.html ^Cruntests.py | Received keyboard interrupt. Stopping web server Stopping web socket server Stopping ssltunnel leakcheck | refcount logging is off, so leaks can't be detected! runtests.py | Running tests: end. Buffered messages finished 0 INFO TEST-START | Shutdown 1 INFO Passed: 0 2 INFO Failed: 0 3 INFO Todo: 0 4 INFO Mode: e10s 5 INFO SimpleTest FINISHED Buffered messages finished SUITE-END | took 3s

Pushed by gbrown@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/d6879c60aa6a Break out of multi-flavor |mach mochitest| with one ctrl-c; r=jmaher