Code completion suddenly stopped working in my viewDidLoad function. However, strangely, autocomplete works properly in other functions. It turns out that autocomplete does not work after a lot of code in a particular function. The viewDidLoad function has around 100 lines of code. And autocomplete becomes extremely slow after this. Autocomplete works properly in other projects.
P.S- The following did not work- Deleting Derived Data, commands in terminal etc. I had installed FuzzyAutocomplete through the Alcatraz plug in, but I deleted Alcatraz soon after. I think the fuzzy autocomplete plug in has still not been uninstalled even though I deleted alcatraz by pasting this into terminal-
rm -rf ~/Library/Application\ Support/Developer/Shared/Xcode/Plug-ins/Alcatraz.xcplugin
I think there is some bug, and fuzzy autocomplete has blocked the Xcode code completion. All of this did not help. What can I do? Please help.
So well, I finally figured this out. I reinstalled Xcode on my laptop, and the problem didn't seem to go away. So I got to know that there was something wrong with my code. Xcode might have probably got stuck while processing that bit of code. So I slowly kept on commenting out one line after the other while checking whether code completion had started to work. I narrowed this down to one code block in my viewDidLoad() function which involved quite a lot of calculation. When I narrowed it down to just this much, Xcode suddenly gave me an error- Expression was too complex to be solved in reasonable time. Consider breaking up the expression in distinct sub-expressions. That line involved a long calculation of addition and subtraction which made Xcode get stuck on it which is why code completion could not find enough memory to run smoothly in that particular function, and Xcode kept on indexing again and again. For some reason, the previously installed copy of Xcode did not give me this error. Thankfully, this copy did. So the problem was sorted.
P.S- I was using Xcode 7.1 which was the latest version.
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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.
I noticed strange behaviour during working with Swift projects. I can't explain it other than Swift sometimes calls wrong method. It is very rare and even adding blank lines to the code could lead that this error is gone.
Let me explain in screenshots what I mean, next I use CoreData example of SwiftDDP project that can be found on Github, but such issues I was able to see in my own projects.
Here we at Todos.swift:74 where you can see breakpoint, I expect that next call should be getId() method of MeteorClient class because it was already instantiated:
After Step Into as you can see the ping() of the same instance is called:
The next two steps into lead to EXC_BAD_ACCESS exception:
In my project I saw this issue fairly often before I stopped using singletons, so it could be related to Swift static memory usage or I don't understand something that is not surprising as I have little experience with multithreading and memory management.
My environment is:
AppCode OC-145.184.11
Xcode Version 7.2.1 (7C1002)
iOS 9.2 SDK
Apple Swift version 2.1.1 (swiftlang-700.1.101.15 clang-700.1.81)
NOTE: Here I use AppCode but the same behavior I was able see in Xcode, and even more if the same issue that reproduces in Xcode could not reproduce in AppCode and vice versa.
Would be thankful if someone can explain this strange behaviour to me.
Thanks!
This just happened on my team, using Swift 2.2. It's really incredibly strange. It's not a threading issue or an async problem, it was a very cut & dry use case. We called one instance method and another one above it got called. I deleted the method that was getting called, and then the one above THAT got called instead. Then I moved the method I was actually calling to a different location in the file, and it looked like multiple properties were getting called.
This is disturbing and worrisome, as now you feel you can't trust your code to run properly.
But we did "solve" it. We moved the method up to the code that was actually getting triggered, and after a little trial & error the right method got called. Not yet sure if this will manifest itself for other methods.
It'd be nice to be able to provide a simple project where this is happening, but it seems highly unlikely that it's possible, and I can't share a snap shot of my code base with Apple. It must be a perfect storm of something to cause a bug with Swift's run time.
I had a similar issue, I think. Couldn't see that the wrong function was being called, but breakpoints on the function that was being called were never hit, and I couldn't step into the function from where it was being called. I added a new function (I called it wtf) with the same parameter list and implementation, and that one worked as expected, so it must have been a weird linking issue in the Swift compiler.
Update: super-cleaning appeared to work (see below), but it doesn't. Looks like I'm leaving my wtf function in.
After super-cleaning the project, it looks like everything's working as expected again:
clean (cmd + shift + k)
clean build dir (cmd + opt + shift + k)
quit XCode
delete derived data (rm -rf ~/Library/Developer/Xcode/DerivedData/*)
FYI, in my case, the function I call is in a generic base class, called from a generic subclass, triggered by a specialized sub-sub-class. As we all know, the generics are still very buggy in the Swift compiler, so that's probably why I encountered this.
Do you have multiple threads running? Maybe a network thread?
I thought I had this issue too but then it turned out my one thread was doing something and because the other thread crashed it stopped the other thread at a random point. I only noticed this thread so it seemed like it crashed at a random #IBAction function.
When I switched to iPhone 6 simulator instead of iPhone 7, it seems to be working correctly now!
Our app was rejected from review because of a mysterious crash. After debugging I found that it was having this same issue - but only for the Release scheme!
So I went through every setting in Build Settings one by one to see if switching it to that of another scheme would fix the issue: changing ENABLE_TESTABILITY to true fixed it......
I've searched around and can't find anything on this.
Using Swift 2 and Xcode Version 7.0.1 (7A1001). Every time I execute something in the debugger console, Xcode crashes.
The project is not very big, and has less than 10 third party frameworks.
I can't think of much more information that's relevant, but I'm sure there's more, so please do ask me if there's anything I should add to my question that would help.
I've of course cleaned build and derived data.
It's driving me insane. Thanks!
UPDATE 16/11/12
Submitted rdar://23559366.
How are you maintaining your third party frameworks? Via Carthage?
If so then this is probably your issue: https://github.com/Carthage/Carthage/issues/924
This is an issue if the location of the /Carthage/Build/iOS folder is in a different location to where it was produced (i.e if it was compiled on a different machine and the absolute file path has changed).
A temporary fix would be to run carthage build --no-use-binaries on your machine to rebuild the symbols using the current absolute file path working around the bug.
But if you wasn't using carthage then its probably not your issue so sorry
I had similar problem with Xcode whenever I hit breakpoint.
In case you see this screen right before your Xcode crashes - you are lucky and my fix might save you. All you need to do is open this window and in the Project Navigator, select any file that you want, so that instead of that white blank view you would get your code. After this you are most likely will be able to successfully stop your app at your breakpoint and perform the debug.
I am not sure why this happens, but I suspect that the reason is Debug View Hierarchy mode, which you might have triggered prior to setting you breakpoint and trying to stop at it. At least this is when it happens to me.
I have similar problem earlier.
If you try to print non-optional variable and unfortunately it holds nil value then it breaks/crash. so that make sure declare all possible variables as "Optional type".
After I installed the latest version of xcode i'm having a very annoying issue.
While I'm coding, xcode goes nuts. Without me doing anything weird, just typing code, xcode stop recognizing classes.
For example: I want to add UITableViewDelegate to my class, but it doesnt recognize it. After i type it manually sometimes it recognize it and it is shown in purple, some other time it doesnt. But both times it won't really consider it, so if I try to write down a method of that delegate, it won't show it.
Other times if I try to call a variable of a certain class, while trying to autocompleting it, it shows <>.
Other times if I try to call any class, let's say I try to type var test = UIActionSheet, it just shows a few elements in the autocomplete list (raw types, primitives, the classes of my main project, but it doesn't show the majority of classes).
It's like it's missing the documentation and the link with the main frameworks...
I'm working on a simple tabbed app from yesterday and it's the 3rd time i started all over because of this issue, thinking that starting over would fix the issue, but it's not working.
If i open a different project while the issue is going on, the other project works ( but i recoded all over my app so it's not that one the issue, and i also have the same issue on other project... it just doesn't affect 2 project at the same time )
i tried deleting derived data
i tried restarting both xcode and the comp
What's going on?
Here are two screenshoots where you can see what's happening:
I had the same problem earlier.
Exit Xcode and delete Derived Data folder here ~/Library/Developer/Xcode
Restart Xcode and you should see the autocomplete working again.
You have to learn how to take it apart and put back together.
Either reinstall Xcode, if it doesn't help, create a new project.
Then copy source files one by one and see when it breaks.
Freshly install the XCode IDE version 6.1
Use CMD + F to find all _element.
Check that if you named one variable _element
The following code may reproduce the error:
class _element:NSObject {
}
let _element:UIImage = UIImage()
// type _element under this line
Suddenly, only code completion which starts with # has stopped working in all Xcode projects in Xcode 6.
About a week ago, after upgrading to Xcode 6.0.1, I tried to use Debug View Hierarchy, then not only Xcode but also my entire Mac system crashed and it restarted. Since then, if I remember correctly, The problem has started to happen.
Most code completions are working correctly, like NSLog().
But, only code completion which starts with #, like #"string", #[array, ...], hasn't been working in all of my Xcode projects. When I type #, I can't see an automatic code completion popup window for NSString, id, NSArray, and so on. The code completion popup window automatically doesn't show up, but when I type the esc key, it shows up.
I tried deleting Derived Data from Organizer in Xcode, but It didn't solve the issue.
I updated Xcode to 6.1 just today, but it didn't work.
I tried re-installing Xcode 6.1 with deleting all files at ~/Library/Developer/Xcode, and it didn't work either.
Even in a new Xcode project, there's the same issue. One of the weirdest points is that this code completion issue happens in my all Xcode projects regardless of when they are created. Also, the code completion for only # doesn't work.
The code completion for # is used very often. It's a sooo pain in the neck... It would be great if you could give me any advice to solve this issue. Thanks!
I believe Apple has changed the behavior of this. So I guess get used to it.
I know it sucks, but at least you can change it to something else.
If someone knows how to get it back to like in Xcode 5 that would be awesome!