how to debug, mocha-chrome not detecting mocha.run

[acthp]

Output:

Mocha-Chrome Failed: mocha was not found in the page within 10000ms of the page loading.
Mocha-Chrome Failed: mocha.run() was not called within 10000ms of the page loading.
  ChromeLauncher Killing Chrome instance 4439 +11s

Thing is, the page works fine when I load it in a browser. I can catch a breakpoint on mocha.run when it is executed, and window.mocha exists (which is what mocha-chrome is looking for). Setting log level to debug doesn't give any more information. How can I debug from here?