I have upgraded Xcode 8 but when I'm debugging, every object showing following error :
expression produced error: error: Couldn't materialize: couldn't get the value of __once: extracting data from value failed
error: errored out in DoExecute, couldn't PrepareToExecuteJITExpression
This seems system level error, so I've already tried all possible solutions but still doest work.
I don't know of any bug that would cause this to happen for all types. Except, if this is a Swift project, make sure that you have cleaned and rebuilt all the swift code you depend on from source. At present, Swift really needs the whole world to be built consistently for debugging to work. If that doesn't help, then we will need more details to figure out what is going wrong.
Might be worthwhile to file a bug with http://bugreporter.apple.com since that makes gathering the data needed to solve the problem easier.
Related
I have recently updated to macOS 13.0 and for that minimum XCode Version required is 14.x series. But my existing project never getting successfully building. Its getting stuck at some point.
Its not getting failed. Build process screenshot is attached below. Its not pointing to any specific class. Seems like there are lots of classes which are getting compiled successfully at last but still build process is stuck at some point:
Seen similar threads like below on apple pages but nothing seems working. Does anyone got resolution?
Xcode 14 project compile error
XCode 14 compile errors immediately disappear or do not appear at all
Something similar has happened to me in the past on a number of occasions. If the Swift compiler is hanging mid-build, usually the issue is that there is some expression that is too complex for Swift to do the type inference on.
What you need to do is first find the exact statement that is causing the hang. This is how I do it:
First find out which source file is causing the problem. Look at the build log to figure this out (the build log can be located by looking at the reports navigator ⌘9 ). Find the build log and click on it. The build log will appear in an editor window.
One of the compiles will still be in progress and its file is the one you want.
The next thing to do is comment out all the code and recompile. This time the compilation will finish (if you have the right file, or there is only one) but probably with a lot of errors. Then you add the code back in, function by function, until one of them causes the compilation to hang again. If it's not obvious which line of the function is causing the problem, comment it out again and then add the lines back one by one until the compilation breaks again.
Once you have located the line, you need to simplify the type inference on that line. If it's a closure, try adding an explicit declaration for its parameters and return type. If it involves some complex array, try adding a type annotation to its declaration. Also try breaking down complex expressions into multiple simpler expressions.
There's no one size fits all answer to this but usually, once you have located the exact line that is causing the problem, it should be reasonably obvious how to fix it.
Background:
Attempting to upgrade large 100k codebase from Swift 2.3 to Swift 4. Was making good progress, fixed ~1000 error. Then, after changing one of our DTO objects to use Any instead of AnyObject (because we had to), the compiler started hanging.
Problem:
When compiling the application will get to a certain file and just get stuck (even after 24 hours). It is not frozen just stuck compiling. I have tried temp removing the file but then it just gets stuck on another file and so on and so on.
Research & Attempts
I've read up on the compiler and how to turn on warnings and flags. I tried looking at -Xfrontend -debug-time-function-bodies and -Xfrontend Xfrontend -warn-long-expression-type-checking but nothing comes up. When I look at the build transcript for the file its stuck on there is no info in the expanded transcript.
Do you know what else I can check? I suspect it has something to do with its inability to infer type given how many Any filled dictionaries we have but without getting better information I have no clue where to go from here.
Do you know how I can get info as to why it's getting stuck on this file and no warnings given?
To followup, it took several days, but by first converting to Swift 3.2 and then Swift 4 (commenting out most code to solve later) I was able to get it to compile in Xcode 9.
NOTE:
It has been a few days and I still am having this problem. One thing that would be helpful, is to know some troubleshooting ideas to try, so I can track down what is causing the crash. Any help that would lead me in the correct direction would be greatly appreciated.
I'm running in Xcode 8.2.1 on the simulator, as well as on several different iOS devices. I get the same problem wherever I go.
I have imported a small mp3 file into my spritekit project, called "cat_meow_1.mp3"
when I select the file, in Xcode, and hit the play button, it plays normally. Incidentally I have tried with various different files in various formats, with the same results.
in my code, which complies okay, when I get to the line:
run(SKAction.playSoundFileNamed("cat_meow_1.mp3", waitForCompletion: true))
I get a crash with the error message,
error: use of undeclared identifier '$r0'
Any suggestions how to debug this problem, or to figure out what I did wrong?
I also tried to preload the sound and make a class property, but got the same error. Here's what it looks like:
UPDATE:
After reinstalling Xcode, I still have the same problem. With certain files, I get white noise, while with other ones I get the error here. What else could be wrong with my system to cause this problem?
UPDATE 2:
tried my experiment on a separate mac, and basically it worked just fine. I reinstalled my OS, and got the same problem, with a little more of an error message this time, which reads:
2017-01-18 18:10:09.397565 sound attempt 2[533:124220] [DYMTLInitPlatform] platform initialization successful
2017-01-18 18:10:11.058506 sound attempt 2[533:124042] Metal GPU Frame Capture Enabled
2017-01-18 18:10:11.059146 sound attempt 2[533:124042] Metal API Validation Enabled
error: use of undeclared identifier '$r0'
warning: could not load any Objective-C class information. This will significantly reduce the quality of type information available.
After a couple days, I finally gave in and used Clean My Mac 3 to completely remove Xcode, as well as any and all related files... I must not have caught everything when previously I uninstalled/reinstalled it, because this time, there were none of my custom settings at all when I ran the reinstalled app.
It works now, thankfully, and I can get back to work.
My code is unable to build on xcode 7. What is Segmentation fault?
A segmentation fault happens when your code tries to access memory that it isn't allowed to access. This is often a sign of an uninitialized reference.
It's not clear to me from your screenshot exactly what is going on, though. Perhaps you could provide more details?
From the screenshot it looks like it is happening when you build your project. If this is correct, you need to create a minimal example that displays the problem i.e a code fragment that crashes the compiler in the same way and then you need to raise a bug report about it with Apple (supplying your minimal example so they can reproduce it).
This has happened to me a couple of times in the past and the way I have identified the bit that crashes the compiler is to comment out everything in the source file and then add it back in function by function.That will narrow the problem down to the function. After that you repeat with the lines of code in the offending function, until you get the line that crashes the compiler.
Along the way you may find a work around to stop the compiler crashing. If you do, do not be tempted to skip reporting the bug to Apple. They need to know.
I receive this error when appending an already-successful build in XCode. What I don't understand is I'm not changing anything when appending, and this error shows up.
I've never used an 'old version of Xcode' as the error implicitly states.
Does anyone know how to get append working on a consistent basis?
This is a very simple project, and I'm using Playhaven and TapForTap SDK's, if that offers any insight.
Turns out, XCode upgraded itself without telling me. :(
I rolled back to the version I was using and all is well.
With no code snippets or error logs, it's very hard to determine what the source of your problem is. There's no way to know if your error is describing the cause of your problem or a symptom of the problem without more information.
I can only offer some suggestions:
My first thought is that you're using a deprecated method in your code somewhere, possibly "Append", which if that is the case, more than likely has an updated counterpart, but you'll have to check documentation regarding that.
If you've used "Append" previously with no errors, then you should look into what exactly you've changed in your new build, and verify that the methods you're using are supported.
If your errors are vague or unhelpful, you can begin the process of elimination and start commenting out blocks of code until it builds successfully, and narrow down the source of the problem significantly.
However, it would be to your benefit to expand your question with more information.