So far, it is an isolated case (1 of about 500 users reporting this behaviour), but I cannot find an explanation. Has anybody ever seen something like this?
Yes and no. At this point, I've been in DTS long enough that I've seen nearly everything fail, and that does include things like "one random user can't access <...>". However, all of those situations have been basically unique issues without any common cause.
Thanks for any ideas/help.
First off, in terms of "what's happening" on the device, the standard approach is to collect a sysdiagnose, open up the console log archive, then start looking for clues. Quinn has a post that describes the basic process; however, the best advice I can give is to get as MUCH information from your user about exactly what they did and when they did it.
A typical log archive contains an ENORMOUS amount of data (1+ million entries), so jumping into a log "blind" is EXTREMELY difficult— not so much "looking for a needle in a haystack" as it is "looking for an oddly colored piece of hay in several hundred acres of wheat". A simple note along the lines of "I launched that app at X time and I clicked the button at Y" makes a huge difference in that process.
Coming at this from a different direction, the "Disk Space Diagnostics (FSMetadata)" profile might be helpful. What that profile actually does is generate a file showing the ENTIRE contents of the iOS devices file system, along with basic file metadata (size, dates, etc.). That has obvious privacy implications, which means it needs to be used carefully; however, sometimes being able to see exactly "what's there" is the best way to understand any failure.
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Kevin Elliott
DTS Engineer, CoreOS/Hardware
