iOS10 filesystem - are files no longer in app container?
<p>For debugging purposes I've often written data to files on iOS using code such as this...</p>

<pre><code>NSString *docsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *filePath = [docsPath stringByAppendingPathComponent:testName];
FILE* resultsFile = fopen([filePath UTF8String],"w");
</code></pre>

<p>...and then gotten the data by downloading the container via Xcode (by selecting the app on the "Window->Devices" screen, and choosing "Download container..." from the "little gear" pop-up menu just below the list of apps.)</p>

<p>I recall this working on iOS 9 and previous, but trying this on iOS 10 on an iPhone 6, I'm finding it doesn't work anymore.  The call to <code>fopen</code> is returning success for <code>/var/mobile/Containers/Data/Application/[uuid]/Documents/testname</code> but the file isn't in the container when I download it.</p>

<p>Shouldn't the file be in the container?  Is it elsewhere?  Or is it simply not possible to dump data to a file and pull it off the phone anymore?</p>