Espresso test error: AppNotIdleException

Question

I turned off all animations on developer options. But I still get this exception when trying to click on one of the buttons.

My app is indeed active and not idle ent

Answer 1

I have been struggling with this problem for the last few days.
Here is a method that I used to identify "violators":

private void dumpThreads() {
    int activeCount = Thread.activeCount();
    Thread[] threads = new Thread[activeCount];
    Thread.enumerate(threads);
    for (Thread thread : threads) {
        System.err.println(thread.getName() + ": " + thread.getState());
        for (StackTraceElement stackTraceElement : thread.getStackTrace()) {
            System.err.println("\t" + stackTraceElement);
        }
    }
}

In my case, Facebook SDK was using the AsyncTask thread pool.