I'm trying to compile a dependent libraries from the source code and I've got this error:
/Applications/Xcode.app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS9.0.sdk/usr/include/unistd.h:446:8:
note: 'fork' has been explicitly marked unavailable here pid_t
fork(void) __WATCHOS_PROHIBITED __TVOS_PROHIBITED;
Is there any way to resolve this issue?
The thing is that I don't actually even need this functionality. When I compile this code for iOS and run it under tvOS then it works.
But I can not submit the application because it contains code compiled for iOS.
What would be the good trick to substitute there a dummy fork() function so it compiles OK (believing that it is not actually used by my specific use-cases).
I don't believe there is a way round this. You cannot create processes under iOS and tvOS is 90% iOS, so the same restriction applies.
You'll have to conditionally compile-out that section of code for iOS/tvOS.
After iPhone app that I'm writing in Swift become quite big (> 150 .swift files + various Objective-C libs), Xcode start behave pretty badly:
every second compilation I get various errors, e.g.:
Command failed due to signal: Segmentation fault: 11
compilation take enormous amount of time (> 2 min on MacBook Pro Retina)
and so on.
I just wonder if everyone has same problems and maybe someone found a way to reduce this nightmare?
What I have done so far — I split project into several dynamic frameworks that I link from main project, it helps to reduce compile time, but introduce some new problems.
I also use iRamDisk to keep DerivedData folder in RAM and periodically delete all files from it, it sometimes helps with SourceKit crashes.
Swift toolchain is still a bit gross, you'll need to use some temporary workarounds until Apple fixes it (see UPDATES below)
Here is a list of items that you can do to keep yourself from going crazy.
Slowness caused by immature Swift compiler
Change your development workflow using Injection for Xcode. Once you installed the plugin, you'll be able to inject code changes in your simulator\device without recompiling. You don't need to hardcode\modify anything in your project. We started using it recently at work and it made a huge impact on our side, even if it doesn't apply to every use case (for example you can't create new functions, you can only modify the existing ones).
Some particular code constructs that the compiler doesn't like and takes too much time to compile. The most common problem is with the Type Checker that slows down compile time exponentially based on how many type checks it needs to do (read more here for practical examples and here for a detailed explanation). In order to identify if you are suffering from this problem you can follow this blog post, you will gather information about the functions that creates slowness by using some compiler additional flags. Alternatively you can use this Xcode plugin to identify the source of the build slowness.
Use dynamic frameworks wisely, where it makes sense. A framework recompilation will be done only when you modify one of its Swift files (dynamic frameworks are only available for iOS >= 7).
Condense code in the same files. Lowering the number of Swift files speeds up the compile process sensibly. You can easily achieve it enabling "Whole module optimization" by adding a user-defined custom flag SWIFT_WHOLE_MODULE_OPTIMIZATION and set it to YES and at the same time set optimization level to none (to disable optimizations that would make it slow) OUTDATED You may consider to use this gist, it's a build script that collapses all your code in a "merge.swift" file.
You'll need to create a new target for it, but it is worth a
try.
Double check things listed here (there are a few some more misc reasons because the compilation is slow)
OUTDATED Try the approach described in this blog post, it involves creating a build script that generates a make file. It requires manual intervention on the build script (it contains the list of swift files).
OUTDATED Try this hacked up incremental compilation technique
UPDATE: Incremental builds introduced on Swift 1.2 (Xcode 6.3)
Apple finally introduced incremental builds with Swift 1.2 (shipped with Xcode 6.3). It's not still perfect, but it's a huge improvement.
From now on a class is recompiled only when it is changed (or when one of the class it depends on has been changed).
However the compiler still can’t understand if the changes to a class are to its interface or not. So any kind of change to a class causes a recompilation of that class and all of its dependencies.
UPDATE: Recompile dependent classes only when public interface changes introduced on Swift 2.1 (Xcode 7.1)
Starting from Swift 2.1 (Xcode 7.1), the dependent classes are recompiled only when you change the public interface of a class, and not at every change. This makes an huge difference in particular for big projects.
Project (mis)configuration (not related to Swift)
Be sure that "Build Active Architecture Only" is YES for debug.
Be sure that you didn't add pre\post compilation scripts that take too much time.
Apple has some advices for speeding up your Xcode build in Technical Note 2190. Have you thought about creating and precompiling an own framework for outsourcing unchanged Swift modules or some/all Objective-C code?
Remove all type inferences in Swift.
This SO topic has some nice ideas and this blog post suggest to
stop generating dSYM bundles and
avoid compiling with -O4 if using Clang.
Although lots of these improvements are related to Objective-C, I am quite sure, that some of them are still relevant for Swift.
The (re)compiling is a known issue that I am sure will be resolved soon. Some recommendations:
Use Objective C where possible - it compiles fast even if it is a part of a Swift project
Split code to frameworks
Specify types instead of leaving it up to the compiler to infer them
Again, there is a good chance that this will be fixed soon, so perhaps it is best not to make big investments in rewriting or reorganizing the code at this point in time.
you could try:
upgrading the amount of RAM in your computer
if you have multiple .swift files that do things on the same view controller, try condensing them into one .swift file per view controller
tweaking the settings under compile sources to see if you have any duplicates or if there are any scripts or settings you can add to make it compile faster...
you can also take a look at this post's answers for some hints as to what you can do to slow down compile time
I've discovered that one of the main causes of segmentation faults and slow compilation is hardcoding big arrays and dictionaries, especially when declaring them as global constants and trying to access values from them from within another .swift file. When I store all that data inside plists, these problems are gone.
In my experience avoid creating the large swift files, when I started a project in my new company, there was a 'UIViewController' with more than 2000 lines, little changes on this file taking much time to build, I made 4 extensions with <500 lines from that class, my speed improvement was incredible.
I am rebuilding an App and at the same time paring it down of unnecessary code and it contains "required frameworks" that I think were left over from copying a previous app shell for building this app. How can I determine if a framework is actually needed. I thought I could just leave them off and build the app and then add them as required to let it build successfully but in the past that has not worked well to my surprise as I have built and tested a previous App without any additional frameworks added and the App built and ran just fine on simulators and actually devices only to find out at submission time I forgot to add the frameworks before submitting it.
I am trying to be proactive and only put in the ones I need. Some, like the MediaPlayer are definitely not needed and I can eliminate them already but some are harder to determine.
Curious if there was an easy way to figure this out.
I am finishing up my first application and researched some methods to make use of two targets in the same project. There are few functions that will reduce the free version and will add adbmob banner.
The various tutorials that follow, the one who worked to differentiate the targets was this:
How to get Target name?
I researched other ways to accomplish this task are old threads and could not make it work.
I tried to add in FREE_VERSION Precompiler macros and many errors occurred. I also tried to add FREE_VERSION in Other C flags within LLVM 5.1 - Custom Compiler flags.
I'm not sure if these methods still work, or if there are better. Does anyone have a more current way to accomplish this or can I use the method I quoted at the beginning of the topic?
You can use a Preprocessor macro to mask off code that should run only in one version or the other, and you can use User-Defined Build Settings to differentiate important fields in your app's property list. Just make sure you produce archives for each version while in the correct build scheme when you're submitting.
However, Apple is becoming less friendly to "upselling", so if your free version asks the user to consider downloading the paid version, it will likely be rejected (they will cite guideline 2.9). To avoid that, you can either make a single version which is free and upgrades with an In-App Purchase, or you can be careful to make sure that the free version doesn't push the user toward the paid version.
I'm running the ARC conversion tool for the first time. I've followed the instructions and dealt with all of the issues/erros in my files that the conversion tool finds before it will actually run. I also have several third party libraries that I've told ARC to skip by unchecking them in the Targets to Convert dialog. After running the tool it shows me a report of all the changed files but no files have been changed. Next I save and try to build the project only to find that I have nearly 1000 build errors due to all the calls to retain and release in my project. It's my understanding that the conversion tool is supposed to remove all calls to retain, release, and autorelease but that isn't the case for me.
Has anybody encountered this problem before and if so how did you solve it? Or is it my responsibility to remove all retains & releases from my app? If so I'm not sure what the point of the conversion tool is. Please advise.
Thanks in advance
I am about to try this on my own rather large project, so I may be back with more questions, but I found this that might help:
http://meandmark.com/blog/2011/11/xcode-4-2-convert-to-arc-troubleshooting/
Are you using GIT repositories for your code? It may not be converting due to the snapshot issue described.
This works better in case you allow it to continue building if errors encountered (Preferences - General). However, not all files are changed or converted completely anyway. But a few regulars will do the dirty job.
In case anyone wants to copy and paste;
\[([\[\w\s\]]+) autorelease\]