I just wanted to start optimizing my app and launched it through Instruments. But no matter which of the tools I use my app crashes immediately when it's launched.
When I run my app normally it does not show any issue. Further I ran it with Instruments a couple of days/weeks ago with no issue. But today it will not even start.
Instruments shows the following (from the short start)
Total Samples Running Time Self Symbol Name
322 322.0ms 92.0% 0,0 Main Thread 0x1734
256 256.0ms 73.1% 0,0 start
64 64.0ms 18.2% 0,0 _dyld_start
2 2.0ms 0.5% 2,0 objc_opt::objc_stringhash_t::hash(char const*, unsigned long) const
9 9.0ms 2.5% 0,0 _dispatch_mgr_thread 0x1752
7 7.0ms 2.0% 0,0 _dispatch_worker_thread3 0x1756
5 5.0ms 1.4% 0,0 _dispatch_worker_thread3 0x1755
4 4.0ms 1.1% 0,0 start_wqthread 0x1754
2 2.0ms 0.5% 0,0 _dispatch_worker_thread3 0x1753
Here I wanted to show a part of the app crash (though likely useless) but it even does not start my app. Aaaarrrggghhhhh
Wait - the console log!
01.03.15 21:57:33,149 Xcode[1831]: DVTAssertions: Warning in /SourceCache/IDEXcode3ProjectSupport/IDEXcode3ProjectSupport-6269/Xcode3Core/LegacyProjects/Frameworks/DevToolsCore/DevToolsCore/SpecificationTypes/BuiltInSpecifications/Compilers/XCGccMakefileDependencies.m:77
Details: Failed to load dependencies output contents from ``/Users/thomaskilian/Library/Developer/Xcode/DerivedData/CaLister-evdxmqajatsxzqeosqkzlmfglmva/Build/Intermediates/CaLister.build/Debug/CaLister.build/Objects-normal/x86_64/ShiftedCell.d''. Error: Error Domain=NSCocoaErrorDomain Code=260 "The file “ShiftedCell.d” couldn’t be opened because there is no such file." UserInfo=0x7ffc7f4732c0 {NSFilePath=/Users/thomaskilian/Library/Developer/Xcode/DerivedData/CaLister-evdxmqajatsxzqeosqkzlmfglmva/Build/Intermediates/CaLister.build/Debug/CaLister.build/Objects-normal/x86_64/ShiftedCell.d, NSUnderlyingError=0x7ffc7f4741b0 "The operation couldn’t be completed. No such file or directory"}. User info: {
NSFilePath = "/Users/thomaskilian/Library/Developer/Xcode/DerivedData/CaLister-evdxmqajatsxzqeosqkzlmfglmva/Build/Intermediates/CaLister.build/Debug/CaLister.build/Objects-normal/x86_64/ShiftedCell.d";
NSUnderlyingError = "Error Domain=NSPOSIXErrorDomain Code=2 \"The operation couldn\U2019t be completed. No such file or directory\"";
}.
Function: void XCGccMakefileDependenciesParsePathsFromRuleFile(NSString *__strong, void (^__strong)(NSString *__strong))
Thread: <NSThread: 0x7ffc7b799b60>{number = 2, name = (null)}
Please file a bug at http://bugreport.apple.com with this warning message and any useful information you can provide.
-> see my own answer
It turns out that Instruments is part of the ongoing Alpha Study called Swift which Apple is currently taking on their "Developers, developers, developers". Thank you, Apple!