I'm trying to ensure that the release build of my MonoTouch app will produce crash logs that I can use, but I'm unable to get any crash logs from the device. Here are the steps I'm taking.
I put some code in my app that would force it to crash when the user touches the screen.
I did a release build and verified that the .dSYM folder is next to the .app folder.
I ran the app on my iPad and touched the screen to make it crash. The app exited instantly.
I did a Sync in iTunes.
I looked under Library\Logs\CrashReporter\MobileDevice[devicename] and [devicename].symbolicated, but there is nothing under there.
I've tried two methods of making the app crash. First way:
SomeObject x = null;
x.SomeFunction();
Second way:
unsafe {
short *p = (short*)0;
for ( int i=0; i < 1000000; i++ )
p[i] = 0;
}
Both methods cause the app to exit instantly, but neither is producing a crash log.
What am I missing here?
It appears that unhandled managed exceptions do not generate a crash log. Could you please file a bug at http://monotouch.net/Support so we can track and fix this issue?
In the mean time you could wrap your Main call in
try {
} catch {}
and log it somewhere and upload it to a web server you have or some such.
Related
I have random crashes in my WinJS application when navigating between pages.
The problem is that these crashes never occurs when the app is attached to the Visual Studio debugger; so I can't find where they come from.
I use the WinJS.Application.onerror event to prevent crashes, and log what happens, but as this works well when I try with a random exception, my "uncatchable" crashes doesn't seem to fire this event (I don't have anything logged).
Do you have any idea of what could cause these crashes, or any solution to find more informations ?
Sometimes errors can't fire the WinJS.Application.onerror for several reasons (in my app, the problem was in an iframe, in a page not using winjs).
When it happens, errors can be found in the event log, under "administrative events"
Found this on this link :
http://www.davepaquette.com/archive/2012/09/15/windows-8-store-app-crash-logs.aspx
Jason gives a good solution to this problem in this video (start at time 14:48). In his example, the app was crashing if you had a callback and navigated to a different page before the callback completed. Could this be the case for your app? Any more details on what is going on when you navigate?
For others (since it seems you already know about this!):
To be able to debug easier, use the WinJS.Application.OnError event. Wire up an event handler that dumps out information about the problem before the app crashes.
WinJS.Application.onerror = function (info) {
var err = {
errorMessage: info.detail.errorMessage,
errorUrl: info.detail.errorUrl,
errorLine: info.detail.errorLine,
errorCharacter: info.detail.errorCharacter,
};
Windows.Storage.ApplicationData.current.localFolder
.createFileAsync("crash.txt", Windows.Storage.CreationCollisionOption.openIfExists)
.then(function (file) {
Windows.Storage.FileIO.appendLinesAsync(file, [JSON.stringify(err)]);
});
};
The final stop for exceptions in JavaScript is actually window.onerror; not every exception will get thrown through WinJS.Application.onerror. Try hooking window.onerror directly.
I am working on an app, where I display the data entered by user in a PDF file. PDF File is also created dynamically.
All this is fine.
I have implemented QuickLook framework to display the pdf file. When I call the QL framework, PDF file id displayed quite fine but when come back to the calling screen, my app crashes without any crash log or memory warnings.
I am calling QL with below code:
[[self navigationController] presentModalViewController:qlPreviewer animated:YES];
logs created are
DiskImageCache: Could not resolve the absolute path of the old directory.
[Switching to process 3070 thread 0x17603]
[Switching to process 3070 thread 0x15503]
This is quite interesting.....
When I run the same program in Instruments to check for leaks and Memory Management, i can only find leaks when PDF document is scrolled and all the pages are viewed.
However, interestingly there is no app crash that I can see.
Also, I did try with ZombieEnabled = YES and without it but no app crash with Instruments.
I am quite clueless on how to interpret this and have been trying different things to solve this. Also, I have tried UIWebView but the result is the same.
I was again trying something to check out the issue and found something interesting.
When i execute the code directly from X-Code - i get the crash in as explained above.
In other instance, if I execute the app by clicking on the app in the sim... no crash
I am yet to check this on device. Can someone confirm the crash on the device?
Also, Google does not have answer to this question.
Thanks in advance for your answers.
Can anyone shed some light on this?
I'm having the exact same issue.
As a workaround, you can disable or remove your 'All Exceptions' breakpoint. This might make debugging a little more difficult, but it's not as bad as having to relaunch the application all the time.
This is the breakpoint causing the issue. I had set it so long ago that I'd forgotten it was there
Deleting application from device helped me to solve this problem.
Maybe also at first you should try "Product > Clean" to ensure that all resources will be copied to your device.
I was able to fix mine with this code:
FirstViewController.h
NSURLRequest* reqObj;
#property(nonatomic, retain) NSURLRequest* reqObj;
FirstViewController.m
reqObj = [NSURLRequest requestWithUrl:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:60.0];
NSURLConnection* conn = [[NSURLConnection alloc] initWithRequest:reqObj delegate:self];
then instead of loading it on my view after this line i waited for the connectionDidFinishLoading then load it to my view
Interesting: This has just started with my app too. No errors when checking for leaks but running the app in the sim actually is causing a Breakpoint, not a crash. I can hit the continue and the app keeps running, no problem.
My issue also is relating to a PDF, but I'm just using a web view to display a PDF from the app bundle. I've checked everything in the dealloc, it's all good, this may be a iOS 5.1 bug. I will update as I learn more.
#JimP, It isn't an iOS 5.1 bug. It has just started happening to my app as well, on iOS5.0. It seems to only affect pdfs of more than one page length, and seems to trigger most commonly on scrolling past the end of the document (although sometimes earlier also). It also seems to happen more often on a second load.
This could happen when you delete the object reference in code but having its reference in xib. Delete the outlet that you no longer need.
Just ran into this problem of loading a pdf file in an App I am converting to iOS 8. This App has been running fine since the first iPhone. I just removed the All Exceptions breakpoint to work around it.
I don't know if it's the same problem but I had an issue where switching from a PDF view to another more than three times via the tab bar controller caused a crash.
Turned out that embedding the views I was switching to within Navigation controllers put a stop to the crashing.
I have a mac app that writes camera data to a file then uploads that file on an [NSTimer] to a server. However, after the camera runs for a while it closes itself and I see this in the log: * QTCaptureDeviceInput warning: The device "FaceTime HD Camera (Built-in)" was closed while still being used in a capture session. Make sure that the session is not running before closing any devices it is using.
No other apps are open that can use the camera in the test case and the object for the device is not being released by me. I have gone so far as to call retain on it to prevent this, to no avail.
I looked at Apple's docs and nowhere that I found did it talk about the camera being shut off by the system, so what could be causing this. In the meantime I have some code that periodically checks if it is open and if it isn't calls open on it.
One thing I forgot I am using this notification and it is being fired: QTCaptureDeviceWasDisconnectedNotification
Well, it took a while but I found the issue. When you you are pulling image data from a running QTCaptureDevice you need to work with individual frames via the following delegate method. If you fail to properly release the buffers on each run the camera will eventually close by itself. Please note the code below is CORRECt; I attached it to help anyone else reading this question. Hope this saves someone the time it costed me...
- (void) captureOutput:(QTCaptureOutput *)captureOutput didOutputVideoFrame:(CVImageBufferRef)videoFrame withSampleBuffer:(QTSampleBuffer *)sampleBuffer fromConnection:(QTCaptureConnection *)connection {
CVBufferRef bufferToBeReleased;
CVBufferRetain(videoFrame);
#synchronized (self) {
imageBufferToRelease = imageIWanted;
imageIWanted = videoFrame;
}
CVBufferRelease(bufferToBeReleased);
}
I'm working with the ID3 framework in Xcode (which has since disappeared off the face of the web - including google cache!).
I'm testing out an import mp3 feature which allows them to edit the tags as they import them. One of the test cases is a corrupt or invalid mp3 with no proper id3 header. The problem I'm having is that when updating the tags of the invalid mp3 (updateFile:), the ID3 framework attempts to use id3V1Tag.m (I assume it falls back to this if it can't find the v2 tag) and this is where I get the Xcode error (whilst running the program, not building):
Xcode could not locate source file: id3V1Tag.m (line: 299)
Even in a release build this crashes the program, so it's not something I can really ignore.
I've tried putting a try/catch block around it but it's not treated as an exception so doesn't get caught. The function to load the tag data for the file returns a BOOL but it appears this only returns false if the given file doesn't exist, so this doesn't help either.
Current code:
[tagData release];
tagData = [[TagAPI alloc] initWithGenreList:nil];
tagsLoaded = [tagData examineFile:exportPath];
if(tagsLoaded) {
[tagData setTitle:title];
[tagData setArtist:artist];
[tagData setComments:comments];
#try {
[tagData updateFile];
}
#catch (id e){
NSLog(#"h");
}
}
The error you're getting is that Xcode is trying to locate your source file id3V1Tag.m in order to show it during debugging. No code you write will affect this.
If you don't have the id3V1Tag.m source file in your framework distro, there's nothing you can do about this, and there's little to do but ignore it (other than seeing if you can avoid causing it to be requested, like not setting a breakpoint in it, not stepping into it, and not crashing in it).
If you do have it, and are building it, then perhaps you're not building with the right debug information, so you'll have to tell us more about your build setup.
So the problem you're having is that your program is crashing when you attempt to compile id3V1Tag.m or while running the program. I'm a bit confused on that.
If its crashing while running maybe this is an issues with a code file missing from a library? How are you reading the ID3 tag information exactly? Is it through your own code or through a 3rd party library/class.
Background
I'm using UKCrashReporter in my app.
I've installed my own Uncaught
Exception Handler.
I'm setting up the
managedObjectContext of the object
activeItemController in
applicationDidFinishLaunching (1)
The Problem
If the managedObjectContext method throws an exception, the crash reporter dialog box only flashes up before the app crashes and so the user never gets to report the crash.
I want my app to continue only after the crash has been reported, not whilst the window is showing.
What I've tried
If UKCrashReporterCheckForCrash()
were an objective C method, I assume
I could call
performSelectorOnMainThread:waitUntilDone:YES
but it's not.
I've looked at some other Stack
Overflow questions about using
Conditional Locks to pause apps,
but I can't understand how I'd use it
for a C function.
How would I go about doing this in a nice way? Do people have any advice
for me? Any responses would be much
appreciated.
The Code
// In app delegate
-(void)applicationWillFinishLaunching:(NSNotification *)aNotification {
UKCrashReporterCheckForCrash(); // A C function which then creates a window if
// it detects a crash has happened.
}
-(void)applicationDidFinishLaunching:(NSNotification *)aNotification {
[activeItemController setMoContextDisk:[self managedObjectContext]];
[activeItemController setMoContextMemory:[self managedObjectContextMemory]];
}
Update 1
I've been asked for more details on what I'm trying to do, so here goes.
The bug that triggered this thinking was an exception when merging managedObjectModels. My app got caught in a loop printing "Uncaught exception" to the console every few milliseconds.
And when I installed the uncaught exception handler before this exception happened, I'd get the described behaviour - my app would fire up, display the crash report dialog briefly, then continue to load and crash again.
Summary - I want to be able to handle errors that happen on startup.
(1) I'm not using bindings to do this, as I thought bindings would make testing the class more problematic.
I think your problem is with thinking of it as "pausing" your app. Think of it more as a different initial UI state. Your attempts to block the run loop will prevent any interactive window from ... well, being interactive. :-)
Your best bet is to show your main UI (and connect data sources, etc) only if the "am I prompting the user to submit a crash report" method says "no, go ahead and start normally". Otherwise, show your window and, when the user sends or declines to send the report, close the window and ask your app controller to continue the normal startup.
I looked at UKCrashReporterCheckForCrash() and it doesn't appear to create a window of any kind. It merely submits the crash. Could you describe what you're doing with more detail?