SIGSEV on [S3Request configureURLRequest:] on Amazon AWS iOS SDK - ios

Question

I have an intermittent crash bug when posting images to an S3 bucket using the iOS SDK.
These crash bugs are formed of 2 errors, but originate in the same area of the SDK.
SEGSEV
0 ofs staff 0x00282616 testflight_backtrace + 382
1 ofs staff 0x00283264 TFSignalHandler + 264
2 libsystem_c.dylib 0x3b656e92 _sigtramp + 42
3 ofs staff 0x001c74a6 -S3Request configureURLRequest (S3Request.m:41)
4 ofs staff 0x001b3c1a -S3AbstractPutRequest configureURLRequest (S3AbstractPutRequest.m:27)
5 ofs staff 0x001c61ee -S3PutObjectRequest configureURLRequest (S3PutObjectRequest.m:62)
6 ofs staff 0x001b2bfe -AmazonS3Client signS3Request: (AmazonS3Client.m:579)
7 ofs staff 0x001b22aa -AmazonS3Client invoke: (AmazonS3Client.m:450)
8 ofs staff 0x001b1298 -AmazonS3Client putObject: (AmazonS3Client.m:134)
9 ofs staff 0x000d511e -OFSAmazonS3Client putObject: (OFSAmazonS3Client.m:41)
10 ofs staff 0x00099b02 -OFSAWSFileUploader upload:forTask:toAWSBucket:accessKey:secret:error: (OFSAWSFileUploader.m:120)
11 ofs staff 0x000d442c -OFSPhotoActivityUploadCell startUpload (OFSPhotoActivityUploadCell.m:104)
12 UIKit 0x354260c4 -UIApplication sendAction:to:from:forEvent: + 72
13 UIKit 0x35426076 -UIApplication sendAction:toTarget:fromSender:forEvent: + 30
14 UIKit 0x35426054 -UIControl sendAction:to:forEvent: + 44
15 UIKit 0x3542590a -UIControl(Internal) _sendActionsForEvents:withEvent: + 502
16 UIKit 0x35425e00 -UIControl touchesEnded:withEvent: + 488
17 UIKit 0x35344420 _UIGestureRecognizerUpdate + 5768
18 CoreFoundation 0x335086cc __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 20
19 CoreFoundation 0x335069c0 __CFRunLoopDoObservers + 276
20 CoreFoundation 0x33506d16 __CFRunLoopRun + 742
21 CoreFoundation 0x33479ebc CFRunLoopRunSpecific + 356
22 CoreFoundation 0x33479d48 CFRunLoopRunInMode + 104
23 GraphicsServices 0x3703d2ea GSEventRunModal + 74
24 UIKit 0x3538f300 UIApplicationMain + 1120
25 ofs staff 0x00082e36 main (main.m:16)
26 libdyld.dylib 0x3b60fb1f start + 3
-__NSCFNumber requestFormat: unrecognized selector sent to instance 0x1d43cfc0
0 CoreFoundation 0x335332a3 __exceptionPreprocess + 163
1 libobjc.A.dylib 0x3b1d897f objc_exception_throw + 31
2 CoreFoundation 0x33536e07 -NSObject(NSObject) doesNotRecognizeSelector: + 171
3 CoreFoundation 0x33535531 ___forwarding___ + 393
4 CoreFoundation 0x3348cf68 _CF_forwarding_prep_0 + 24
5 ofs staff 0x001f84a7 -S3Request configureURLRequest (S3Request.m:41)
6 ofs staff 0x001e4c1b -S3AbstractPutRequest configureURLRequest (S3AbstractPutRequest.m:29)
7 ofs staff 0x001f71ef -S3PutObjectRequest configureURLRequest (S3PutObjectRequest.m:64)
8 ofs staff 0x001e3bff -AmazonS3Client signS3Request: (AmazonS3Client.m:579)
9 ofs staff 0x001e32ab -AmazonS3Client invoke: (AmazonS3Client.m:450)
10 ofs staff 0x001e2299 -AmazonS3Client putObject: (AmazonS3Client.m:134)
11 ofs staff 0x0010611f -OFSAmazonS3Client putObject: (OFSAmazonS3Client.m:41)
12 ofs staff 0x000cab03 -OFSAWSFileUploader upload:forTask:toAWSBucket:accessKey:secret:error: (OFSAWSFileUploader.m:120)
13 ofs staff 0x0010542d -OFSPhotoActivityUploadCell startUpload (OFSPhotoActivityUploadCell.m:104)
14 UIKit 0x354260c5 -UIApplication sendAction:to:from:forEvent: + 73
15 UIKit 0x35426077 -UIApplication sendAction:toTarget:fromSender:forEvent: + 31
16 UIKit 0x35426055 -UIControl sendAction:to:forEvent: + 45
17 UIKit 0x3542590b -UIControl(Internal) _sendActionsForEvents:withEvent: + 503
18 UIKit 0x35425e01 -UIControl touchesEnded:withEvent: + 489
19 UIKit 0x35344421 _UIGestureRecognizerUpdate + 5769
20 CoreFoundation 0x335086cd __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 21
21 CoreFoundation 0x335069c1 __CFRunLoopDoObservers + 277
22 CoreFoundation 0x33506d17 __CFRunLoopRun + 743
23 CoreFoundation 0x33479ebd CFRunLoopRunSpecific + 357
24 CoreFoundation 0x33479d49 CFRunLoopRunInMode + 105
25 GraphicsServices 0x3703d2eb GSEventRunModal + 75
26 UIKit 0x3538f301 UIApplicationMain + 1121
27 ofs staff 0x000b3e37 main (main.m:16)
28 libdyld.dylib 0x3b60fb20 start + 0
Both errors are focussed around line 41 of S3Request.m which reads
[self.urlRequest setValue:self.host forHTTPHeaderField:kHttpHdrHost];
These errors are intemittent and so far I have been unable to replicate the issue exactly, so don't know what the value of self.host when the app crashes.
When the upload succeeds, the value for host is the correct bucket name.
To try and replicate this I have tried to run the requests with the host name set to nil, set to an incorrect bucket name, on wifi, 3G and with no connectivity but none of these conditions causes either condition to occur.
Does anyone know what is causing these issues and therefore what I may have to do to fix them?
===UPDATE===
I finally managed to replicate it, i have no idea how. I just got the SIGSEV.
This is the status of the request object at the the S3Request object at the time of the error
(S3PutObjectRequest) S3PutObjectRequest = {
S3AbstractPutRequest = {
S3Request = {
AmazonServiceRequest = {
NSObject = {
isa = OFSS3PutObjectRequest
}
httpMethod = 0x004bde08 #"GET"
parameters = 0x00000000
endpoint = 0x004c3a38 #"https://s3.amazonaws.com"
userAgent = 0x1d427b60 #"aws-sdk-iOS/1.4.4 iPhone-OS/6.0.1 en_GB"
credentials = 0x00000000
urlRequest = 0x1d1165f0
urlConnection = 0x1d04d680
responseTimer = 0x00000000
requestTag = 0x00000000
serviceName = 0x00000000
regionName = 0x00000000
hostName = 0x00000000
delegate = 0x1c567ba0
}
authorization = 0x00000000
contentLength = 0
contentType = 0x004b9e28 #"image/jpeg"
date = 0x1d0e8340 <not an Objective-C object>
securityToken = 0x00000000
bucket = 0x1d4464f0 #"*****"
key = 0x1d1eb040 #"id_C78ACBEA_58163_0.jpg"
subResource = 0x00000000
}
cannedACL = 0x00000000
fullACL = 0x00000000
storageClass = 0x00000000
serverSideEncryption = 0x00000000
metadata = 0x1d2d6700 0 key/value pairs
}
expiresSet = NO
cacheControl = 0x00000000
contentDisposition = 0x00000000
contentEncoding = 0x00000000
contentMD5 = 0x00000000
filename = 0x00000000
data = 0x1d1a9f00 3814479 bytes
stream = 0x00000000
expect = 0x00000000
generateMD5 = NO
expires = 0
redirectLocation = 0x00000000
}