handle files that we can not dump due to permission errors
handle files that we can not dump due to permission errors

Permission errors result in an IOError which, when not handled, would
throw an exception and thus terminate the pipe handler thread without
closing the pipe handle - leaving the caller to wait forever.

cuckoobox/cuckoo,cuckoobox/cuckoo,cuckoobox/cuckoo,cuckoobox/cuckoo,cuckoobox/cuckoo