Mobile Client Crash Logs Ali Rantakari Mobile Fortnightly • 9.8.2013 

Why • You might have bugs that you don’t know about • Users will not send you “steps to reproduce” — they will leave a zero-star review that says “shit dont work” • If you find out (or the client finds out) that there is a crasher in the released build, you’ll want to fix it ASAP • If you don’t know how to reproduce it, you’ll need the stack trace 

How Use a service Do it yourself 

Why use a service • Aggregation — a single bug can generate thousands of crash log reports, but you only want to look at a single instance and ignore the rest • (Semi)automatic symbolication for iOS (in some services, just upload the .dSYM of each build — in others, even this is not required) • Features for searching, browsing, and filtering crashes based on OS/app version, or other device state variables • Project management tool integrations (bug trackers etc.) 

Services • Mobile OS SDKs for iOS, Android, WP… • Symbolication • Custom report metadata • Looks like they are trying to be more “enterprise- like” • My limited experience: seemed pretty good • 3rd party SDKs for iOS and Android • Symbolication (client-side) • Custom report metadata • Pretty much meant for server-side (Ruby) apps; mobile apps not a “good fit” • My experience: I wouldn’t recommend for mobile apps • Only iOS SDK (Android coming later) • Symbolication • Custom report metadata • I have no experience 

Services • Mobile OS SDKs for iOS, Android, WP… • Symbolication (paying customers only; server- or client-side) • Custom report metadata • My limited experience: seemed pretty good • Mobile OS SDKs for iOS, Android, WP… • SaaS or self-hosted (QuincyKit) • Custom report metadata: one string (iOS) or none (WP) • Well-known • I have no experience • SDKs for iOS and Android only • Symbolication (client-side) • Custom report metadata • They act like they’re “Invite only” and make you jump through hoops to start using it • Owned by Twitter nowadays (WTF.) • Well-known • Based on some quick testing, seems very polished 

Which one to try? Go ahead Go ahead (if only iOS + Android) Go ahead Go ahead (Futu has an account?) Forget it. Go ahead (if only iOS) FREE $ $ SELF HOST FREE BASIC FREE BASIC FREE 

Which one to try? Go ahead Go ahead (if only iOS + Android) Go ahead Go ahead (Futu has an account?) Forget it. Go ahead (if only iOS) FREE $ $ SELF HOST FREE BASIC FREE BASIC FREE Android 

Which one to try? Go ahead Go ahead (if only iOS + Android) Go ahead Go ahead (Futu has an account?) Forget it. Go ahead (if only iOS) FREE $ $ SELF HOST FREE BASIC FREE BASIC FREE Windows Phone 

Why do it manually • No existing services fulfill requirements, whatever they may be • Client doesn’t want to use a service for whatever reason • Be a good consultant and help them make a good decision • “We want it in our own datacenter” is not reason enough to do it manually → HockeyApp (QuincyKit) can be self-hosted 

PLCrashReporter Catch Crashes void myprefix_initCrashReporting() { if (PLCrashReporter.sharedReporter.hasPendingCrashReport) myprefix_handlePendingCrashReport(); NSError *crashLogEnablingError; if (![PLCrashReporter.sharedReporter enableCrashReporterAndReturnError:&crashLogEnablingError]) { // Deal with error } } Manually 

PLCrashReporter Catch Crashes void myprefix_handlePendingCrashReport() { NSError *crashLoadError; NSData *crashData = [PLCrashReporter.sharedReporter loadPendingCrashReportDataAndReturnError:&crashLoadError]; if (crashData == nil) { // Handle the error [PLCrashReporter.sharedReporter purgePendingCrashReport]; return; } NSError *reportGenerationError; PLCrashReport *crashReport = [[PLCrashReport alloc] initWithData:crashData error:&reportGenerationError]; if (crashReport == nil) { // Handle the error [PLCrashReporter.sharedReporter purgePendingCrashReport]; return; } NSString *formattedCrashReport = [PLCrashReportTextFormatter stringValueForCrashReport:crashReport withTextFormat:PLCrashReportTextFormatiOS]; [PLCrashReporter.sharedReporter purgePendingCrashReport]; // Do something with the crash report } Manually 

Symbolication This is not very useful: Thread 0: 0 libsystem_kernel.dylib 0x3af45eb4 0x3af45000 + 3764 1 CoreFoundation 0x32d88045 0x32cf1000 + 618565 2 CoreFoundation 0x32d86d5f 0x32cf1000 + 613727 3 CoreFoundation 0x32cf9ebd 0x32cf1000 + 36541 4 CoreFoundation 0x32cf9d49 0x32cf1000 + 36169 5 GraphicsServices 0x368bd2eb 0x368b8000 + 21227 6 UIKit 0x34c0f301 0x34bb8000 + 357121 7 myappname 0x00089ebf 0x7d000 + 52927 Manually 

Symbolication Save the .xcarchive of each public release! (put them into the VCS) Manually 

Symbolication Save the .xcarchive of each public release! (put them into the VCS) • This preserves the debug symbols for the binary • Dropping an .xcarchive into the Xcode organizer allows the auto-symbolication features to work Manually 

Symbolication #!/bin/bash # # Symbolicates a single crash log to stdout. # export DEVELOPER_DIR="`xcode-select -print-path`" "$DEVELOPER_DIR/Platforms/iPhoneOS.platform/Developer/Library/ PrivateFrameworks/DTDeviceKit.framework/Versions/A/Resources/ symbolicatecrash" "$@" Manually 

Symbolication 11 myappname 0x000ada99 my_reticulateSplines() (MYReticulation.m:18) 11 myappname 0x000ada99 0xab000 + 10905 Instead of this: you’ll see this: $ symbolicatecrash.sh crashlogfile.crash Manually 

Catch Crashes private void RootFrame_NavigationFailed( object sender, NavigationFailedEventArgs e) { if (System.Diagnostics.Debugger.IsAttached) { System.Diagnostics.Debugger.Break(); } else { // Do something with `e.Exception` // (use .StackTrace) } } private void Application_UnhandledException( object sender, ApplicationUnhandledExceptionEventArgs e) { if (System.Diagnostics.Debugger.IsAttached) { System.Diagnostics.Debugger.Break(); } else { // Do something with `e.ExceptionObject` // (use .StackTrace) } } Manually 

Symbolication • StackFrame::GetFileName() is marked “security critical” and thus cannot be used ☹ • StackFrame::GetFileLineNumber() either throws an exception or always returns zero ☹ • Exception::StackTrace might contain file names and line numbers (?) but it’s just a string Manually var trace = new StackTrace(exception); StackFrame[] frames = trace.GetFrames();