iOS tools for debugging dynamic libraries - ios

I am trying to understand how dynamic linking works on iOS 8 and would like to print the location of the resolved libraries when the app launches. Are there any tools for doing this? In crash reports when a dylib is not found there is some info about search paths, but I can't find this info in a non-crashing execution.
Specifically, I am trying to understand a scenario which is working, but which I didn't think would:
Swift Framework (Foo): Dynamic Library Install Name is #rpath/Foo.framework/Foo
Swift app (Bar): Runtime Search Paths is #executable_path/Frameworks
The app does NOT have any Embedded Binaries (General -> Embedded Binaries), and does NOT embed the framework as a bundle resource (Build Phases -> Copy Bundle Resources).
In the generated Bar.app folder there is a Frameworks directory, but it does not contain Foo, and Foo is not contained anywhere else within Bar.app. I do not see how is it possible for Foo to be resolved since the framework is embedded and should be unavailable?

I found what I was looking for, as documented by Apple under a document called Technical Note TN2239 iOS Debugging Magic. In this document there is a section describing various environment variables that can bet set which will force the dynamic linker to write out useful debugging information.
After setting these variables in Xcode (Edit Scheme -> Run -> Arguments -> Environment Variables) I get detailed information about how and what the linker is resolving to.

Related

The bundle at … contains disallowed file 'Frameworks'

I'm trying to deploy a .dylib library wrapped in a framework, and I'm experiencing the following issue: 'ERROR ITMS-90206: "Invalid Bundle. The bundle at X.app/Frameworks/PoemsRecommender.framework' contains disallowed file 'Frameworks'."
It looks like there's a framework nested in a framework:
Things I tried:
Remove "Frameworks" folder in the "Run Script" phase (it actually helps with submission but the app crashes because it can't find the dylib which is in the Frameworks folder)
Change "Frameworks" to "Shared Frameworks" in "Embed Frameworks"
Disable "Always Embed Swift.."
Reason
The error message indicates that you are trying to package a framework that has its own frameworks embedded inside.
This is not currently supported through traditional framework embedding
The fix is, unfortunately, to link all frameworks separately in your main target.
How do I know?
When you see this error X.app/Frameworks/PoemsRecommender.framework contains disallowed file 'Frameworks'."
Apple is explicitly saying that a framework that embeds a "Frameworks" folder is disallowed. There is a great discussion here that goes into a lot more detail.
Recommended Solution
Package your frameworks separately and link them all manually. Apple has good guidelines here
Not Recommended but will achieve your goal
If you must use a single framework, there is quite a bit of work involved. Effectively you want to create an Umbrella framework that will mask all underlying frameworks. This can get messy if you ever decide to link those sub-frameworks in other parts of your application. Since your question is vague on the details I cannot ascertain if this will affect you.
There are a number of resources that can guide you through the laborious process.
Effectively the steps involve creating an aggregate target that can use a build script to bind all your frameworks at runtime.
I have done this in the past and we ran into lots of issues on the way and I would not recommend this approach. In the past we had a white-labelled SDK that consisted of a number of internal frameworks that were binded by an aggregate target. More often than not it was difficult to maintain and difficult to understand by new team members. Eventually we just migrated to multiple frameworks.
I think Apple has their own tooling to support how they do it but, sadly, it is not available to us peasants.

How to build iOS framework with XCode 6

I know of familiar tutorials on this, but introduction of framework XCode 6 template has changed the game.
I already watched WWDC 2014 video about building modern frameworks but it talks more about building extensions, framework & app all inside single project. It does not specify if the framework I make with it is truly reusable across any project.
I am building framework the XCode 6 way (File->New Project->Framework and Library->Cocoa Touch Framework), but when I import it inside my test app project (separate from framework project) - I keep getting various errors.
Example: Include of non-modular header inside framework, and so on.
I know this is not what it says, and there are quite some missing steps in whatever I am doing. The older tricks may have worked for everyone, but I simply don't find which way to follow after XCode 6.
For example, there is some folder structure that a framework needs, but XCode 6 doesn't comply to it while building it. Is it right? If not, how can I change the way the XCode builds framework folder hierarchy?
Do I go back to old school or am I screwing some tiny thing in XCode 6 that I am unable to create a reusable framework?
I am not sure if you are trying to build a framework with Objective-C or Swift as your question doesn't state it. I've encountered errors you are mentioning with Swift so I'll give you my method to build Swift frameworks.
I found the process for Objective-C to be very straightforward and well documented, so I'll skip this.
As for Swift, there are a few things to consider. First, Swift static libraries are not supported, so you must exclusively use a framework (aka dynamic library) when linking an app to a library.
Here are the steps:
Create the Framework using New > Project under IOS > Framework & Library, select Cocoa Touch Framework
To avoid the "ld: warning: directory not found for option..." goto Library Search Paths in Build Settings for your target and delete the paths.
You can't mix Objective-C with Swift so don't even consider adding the Swift-Header bridge file in your code.
There are some cases in swift where you need to import code from unexposed Frameworks. I've successfully used the module-map inside the framework to deal with these case.
I also select CLANG_ALLOW_NON_MODULAR_INCLUDES_IN_FRAMEWORK_MODULES = YES in the Build Settings to solve 'include of non-modular header inside framework module'. That seems to work
I make sure that the header file that gets generated is marked as Public (not Project). Click on the file and you'll see the selection in the inspector under 'Target Membership'
You may run into some bizarre error messages when building. Xcode has a tendency to report linker errors when your code can't compile correctly resulting in missing files the linker needs to output its binaries. Sometimes XCode won't show the errors in the files you are compiling and you need to go manually on the build output and go back to the files. Some other time, you'll get a problem where you need to delete the cache. Those issues I call XCode blues and deal with it constantly. I found this type of problems happens more often when building libraries. The rest should work as expected.

Don't we need to link framework to XCode project anymore?

Base on this question
Why don't iOS framework dependencies need to be explicitly linked to a static library
I read the selected answer and still don't understand so I made an example project
Test Project on Github
In the test project, I remove all framework from Link Binary With Libraries and File navigation for both main project and the static library (including Foundation.framework and UIKit.framework too), basically, both project link to 0 frameworks.
Questions are
In static library, it's including MapKit/MapKit.h without referencing the Mapkit.framework to the project, why is its still working?
In main project, I remove UIKit.framework and Foundation.framework from the project, why is it still working?
Since it's working for now, will there be any issue later?
Thank you for your comment.
P.S. By working, I mean I can run on the simulator and I can archive the main project without any error.
Edit 25/07/2014
I tried with the real app that I'm working on, it's the same.
I highlight Foundation, UIKit, CoreData and 10 another frameworks in File Navigation, well, all of them.
Uncheck the target in Utilities Panel --> Target Membership
Build : Pass, Run : Pass
Every functionality of my app is still working as expected. I don't get this.
Check your project build settings. Underneath LLVM 5.1 — Language — Modules you should see the option 'Link Frameworks Automatically'. In your case it sounds like it's set to 'YES', the default.
In that case, instead of producing an error when you reference a class that the compiler doesn't know, it'll figure out which Framework contains that class and link it. In your code it'll be MKMapView or one of the other MapKit classes that triggers the linkage.
EDIT: from the relevant 'What's New?' document:
Auto Linking is enabled for frameworks imported by code modules. When
a source file includes a header from a framework that supports
modules, the compiler generates extra information in the object file
to automatically link in that framework. The result is that, in most
cases, you will not need to specify a separate list of the frameworks
to link with your target when you use a framework API that supports
modules.
Another way of looking at it is that the compiler is smart enough to mutate #import to #import when the framework has been built appropriately. All system frameworks have been.
To elaborate #Tommy's answer, a framework that supports modules satisfies the following 2 conditions:
Under Build Settings > Packaging
Define Modules is set to YES
Module Map File exists.
So, if you're certain that the framework you're using in your code modularizes like that, you can choose to not explicitly add it in the link phase as it will be automatically added as long as in the project file, under Apple Clang - Language - Modules, The option Link Frameworks Automatically is set to YES.

iOS app with framework crashed on device, dyld: Library not loaded, Xcode 6 Beta

This crash has been a blocking issue I used the following steps to reproduce the issue:
Create a Cocoa Touch Framework project
Add a swift file and a class Dog
Build a framework for device
Create a Single View application in Swift
Import framework into app project
Instantiate swift class from the framework in ViewController
Build and run an app on the device
The app immediate crashed upon launching, here is console log:
dyld: Library not loaded: #rpath/FrameworkTest03.framework/FrameworkTest03
Referenced from: /var/mobile/Applications/FA6BAAC8-1AAD-49B4-8326-F30F66458CB6/FrameworkTest03App.app/FrameworkTest03App
Reason: image not found
I have tried to build on iOS 7.1 and 8.0 devices, they both have the same crash. However, I can build an app and run on the simulator fine. Also, I am aware that I can change the framework to form Required to Optional in Link Binary With Libraries, but it did not completely resolve the problem, the app crashed when I create an instance of Dog. The behavior is different on the device and simulator, I suspect that we can't distribute a framework for the device using a beta version of Xcode. Can anyone shed light on this?
In the target's General tab, there is an Embedded Binaries field. When you add the framework there the crash is resolved.
Reference is here on Apple Developer Forums.
For iOS greater than or equal to 8
Under the target's General tab, in the Embedded Binaries section add the framework. This will copy the framework into the compiled so that it can be linked to at runtime.
Why is this happening? : because the framework you are linking to is compiled as a dynamically linked framework and thus is linked to at runtime.
** Note:** Embedding custom frameworks is only supported in iOS > 8 and thus an alternative solution that works on older versions of iOS follows.
For iOS less than 8
If you influence this framework (have access to the source code/build process) you may change this framework to be statically linked rather than dynamically linked. This will cause the code to be included in your compiled app rather than linked to at runtime and thus the framework will not have to be embedded.
** How:** Under the framework's Build Setting tab, in the Linking section, change the Mach-O Type to Static Library. You should now not need to include the framework under embedded binaries.
Including Assets: To include things such as images, audio, or xib/nib files I recommend creating a bundle (essentially a directory, more info here bit.ly/ios_bundle) and then load the assets from the bundle using NSBundle.
Just dragging the framework into your project isn't going to be good enough. That is like being in the same ballpark but not being able to find your kids. Follow these steps:
1) Create your framework
Develop your framework.
Once your development is complete, COMMAND+B build your framework and ensure you receive "Build Succeeded".
2) Access your framework
Once your framework project successfully builds it will then be ready for you to access in your Products folder in your project.
Right click on your .framework and select "Show in Finder".
3) Place framework in your project
Drag and drop the .framework from your Finder window to your app project's "Framework" folder.
4) Configure app project for framework
Select the top level in your project
Choose your target
Go to "Build Phases", then "Link Binary with Libraries", and ensure that your framework is included with optional selected.
Still in "Build Phases", go to the upper left and select the + button. In the drop down choose "New Copy Files Phase".
Scroll down to the new "Copy Files" section and ensure that you set Destination to "Frameworks". Leave the subpath empty. Then click the + button at the bottom left.
You will be presented with your project hierarchy. Scroll down to the "Frameworks" folder that you added the framework to in step 3, or search for it in the search bar at the top. Select your framework and click "Add".
Ensure that your framework is included with "Code Sign On Copy" selected.
5) Clean, then run your project
COMMAND+SHIFT+K
COMMAND+R
Firstly Try to build after Command+Option+Shift+K .If still fails then do below steps.
If anybody is facing this error in Xcode 8 then change your framework status to Optional instead of Required under the General Tab of your target.
I created a framework using Swift3/Xcode 8.1 and was consuming it in an Objective-C/Xcode 8.1 project. To fix this issue I had to enable Always Embed Swift Standard Libraries option under Build Options.
Have a look at this screenshot:
I had to (on top of what mentioned here) add the following line to Runpath Search Paths under Build Settings tab:
#executable_path/Frameworks
I got same kind of issue in iOS 9.x version
ISSUE IS: App crashes as soon as I open the app with below error.
dyld: Library not loaded: /System/Library/Frameworks/UserNotifications.framework/UserNotifications
Referenced from: /var/containers/Bundle/Application/######/TestApp.app/TestApp
Reason: image not found
I have resolved this issue by changing Required to Optional in Linked Frameworks and Libraries for UserNotifications.framework framework.
You need to add the framework to a new Copy Files Build Phase to ensure that the framework is copied into the application bundle at runtime..
See How to add a 'Copy Files build phase' to my Target for more information.
Official Apple Docs: https://developer.apple.com/library/mac/recipes/xcode_help-project_editor/Articles/CreatingaCopyFilesBuildPhase.html
If you're using Xcode 11 or newer:
Navigate to the settings of your target and select General.
Scroll down to Frameworks, Libraries and Embedded Content.
Make sure the Embed & Sign or Embed Without Signing value is selected for the Embed option if necessary.
runtime error: dyld: Library not loaded: #rpath/<some_path>
It is a runtime error that is caused by Dynamic Linker
dyld: Library not loaded: #rpath/<some_path>
Referenced from: <some_path>
Reason: image not found
The error Library not loaded with #rpath indicates that Dynamic Linker cannot find the binary.
Check if the dynamic framework was added to the front target General -> Frameworks, Libraries, and Embedded Content (Embedded Binaries). It is very simple to drag-and-drop a framework to project with Copy items if needed[About] and miss to add the framework as implicit dependency in
Frameworks, Libraries, and Embedded Content(or check in Add to targets). In this case during compile time Xcode build it as success but when you run it you get runtime error
Check the #rpath setup between consumer(application) and producer(dynamic framework):
Dynamic framework:
Build Settings -> Dynamic Library Install Name
Application:
Build Settings -> Runpath Search Paths
Build Phases -> Embed Frameworks -> Destination, Subpath
Framework's Mach-O file[About] - Dynamic Library and Application's Frameworks, Libraries, and Embedded Content[About] - Do Not Embed.
Dynamic linker
Dynamic Library Install Name(LD_DYLIB_INSTALL_NAME) which is used by loadable bundle(Dynamic framework as a derivative) where dyld come into play
Dynamic Library Install Name - path to binary file(not .framework). Yes, they have the same name, but MyFramework.framework is a packaged bundle with MyFramework binary file and resources inside.
This path to directory can be absolute or relative(e.g. #executable_path, #loader_path, #rpath). Relative path is more preferable because it is changed together with an anchor that is useful when you distribute your bundle as a single directory
absolute path - Framework1 example
//Framework1 Dynamic Library Install Name
/some_path/Framework1.framework/subfolder1
Relative path allows you to define a path in a dynamic way.
#executable_path
#executable_path - relative to executable binary which loads framework
use case: Dynamic framework inside Application(application binary path
is #executable_path) or more complex example with App Extension[About] which is a part of Containing App with Dynamic Framework inside. There 2 #executable_path for Application target (application binary path is #executable_path) and for App Extension target(App Extension binary path is #executable_path)) - Framework2 example
//Application bundle(`.app` package) absolute path
/some_path/Application.аpp
//Application binary absolute path
/some_path/Application.аpp/subfolder1
//Framework2 binary absolute path
/some_path/Application.аpp/Frameworks/Framework2.framework/subfolder1
//Framework2 #executable_path == Application binary absolute path <-
/some_path/Application.аpp/subfolder1
//Framework2 Dynamic Library Install Name
#executable_path/../Frameworks/Framework2.framework/subfolder1
//Framework2 binary resolved absolute path by dyld
/some_path/Application.аpp/subfolder1/../Frameworks/Framework2.framework/subfolder1
/some_path/Application.аpp/Frameworks/Framework2.framework/subfolder1
#loader_path
#loader_path - relative to bundle which causes framework to be loaded. If it is an application than it will be the same as #executable_path
use case: framework with embedded framework - Framework3_1 with Framework3_2 inside
//Framework3_1 binary absolute path
/some_path/Application.аpp/Frameworks/Framework3_1.framework/subfolder1
//Framework3_2 binary absolute path
/some_path/Application.аpp/Frameworks/Framework3_1.framework/Frameworks/Framework3_2.framework/subfolder1
//Framework3_1 #executable_path == Application binary absolute path <-
/some_path/Application.аpp/subfolder1
//Framework3_1 #loader_path == Framework3_1 #executable_path <-
/some_path/Application.аpp/subfolder1
//Framework3_2 #executable_path == Application binary absolute path <-
/some_path/Application.аpp/subfolder1
//Framework3_2 #loader_path == Framework3_1 binary absolute path <-
/some_path/Application.аpp/Frameworks/Framework3_1.framework/subfolder1
//Framework3_2 Dynamic Library Install Name
#loader_path/../Frameworks/Framework3_2.framework/subfolder1
//Framework3_2 binary resolved absolute path by dyld
/some_path/Application.аpp/Frameworks/Framework3_1.framework/subfolder1/../Frameworks/Framework3_2.framework/subfolder1
/some_path/Application.аpp/Frameworks/Framework3_1.framework/Frameworks/Framework3_2.framework/subfolder1
#rpath - Runpath Search Path
Framework2 example
Previously we had to setup a Framework to work with dyld. It is not convenient because the same Framework can not be used with a different configurations. Since this setup is made on Framework target side it is not possible to configure the same framework for different consumers(applications)
#rpath is a compound concept that relies on outer(Application) and nested(Dynamic framework) parts:
Application:
Runpath Search Paths(LD_RUNPATH_SEARCH_PATHS) - #rpath - defines a list of templates which will be substituted with #rpath. Consumer uses #rpath word to point on this list
#executable_path/../Frameworks
Review Build Phases -> Embed Frameworks -> Destination, Subpath to be sure where exactly the embed framework is located
Dynamic Framework:
Dynamic Library Install Name(LD_DYLIB_INSTALL_NAME) - points that #rpath is used together with local bundle path to a binary
#rpath/Framework2.framework/subfolder1
//Application Runpath Search Paths
#executable_path/../Frameworks
//Framework2 Dynamic Library Install Name
#rpath/Framework2.framework/subfolder1
//Framework2 binary resolved absolute path by dyld
//Framework2 #rpath is replaced by each element of Application Runpath Search Paths
#executable_path/../Frameworks/Framework2.framework/subfolder1
/some_path/Application.аpp/Frameworks/Framework2.framework/subfolder1
*../ - go to the parent of the current directory
otool - object file displaying tool
//-L print shared libraries used
//Application otool -L
#rpath/Framework2.framework/subfolder1/Framework2
//Framework2 otool -L
#rpath/Framework2.framework/subfolder1/Framework2
//-l print the load commands
//Application otool -l
LC_LOAD_DYLIB
#rpath/Framework2.framework/subfolder1/Framework2
LC_RPATH
#executable_path/../Frameworks
//Framework2 otool -l
LC_ID_DYLIB
#rpath/Framework2.framework/subfolder1/Framework2
install_name_tool change dynamic shared library install names using -rpath
CocoaPods uses use_frameworks![About] to regulate a Dynamic Linker
[Vocabulary]
[Java ClassLoader]
Add the framework in Embedded Binaries
Then Clean and Build.
Surprisingly, not all of the necessary pieces are documented here, at least for Xcode 8.
My case was a custom-built framework as part of the same workspace. It turns out it was being built incorrectly. Based on jeremyhu's last response to this thread:
https://forums.developer.apple.com/thread/4687
I had to set Dynamic Library Install Name Base (DYLIB_INSTALL_NAME_BASE) under Build Settings of the Framework Project and then rebuild it. It was incorrectly set to $(LOCAL_LIBRARY_DIR) and I had to change it to #rpath.
So in the link processing stage in the App Project, it was instructing the host App to dynamically load the framework at runtime from /Library/Frameworks/fw.Framework/fw (as in, the root of the runtime filesystem) rather than path-to-App/Frameworks/fw.Framework/fw
Regarding all the other settings: it does have to be in 3 places in Build Phases, but these are all set at once when you just add it to the Embedded Binaries setting of the General tab of the hosting App.
I did not have to set up an extra Copy Files phase, which seems intuitively redundant with respect to the embedding stage anyway. By checking the tail end of the build transcript we can assure that that's not necessary.
PBXCp /Users/xyz/Library/Developer/Xcode/DerivedData/MyApp-cbcnqafhywqkjufwsvbzckecmjjs/Build/Products/Debug-iphoneos/MyFramework.framework
[Many verbose lines removed, but it's clear from the simplified transcript in the Xcode UI.]
I still have no idea why Xcode set the DYLIB_INSTALL_NAME_BASE value incorrectly on me.
Recently ran into this issue with importing CoreNFC on older iphones (e.g. iPhone 6) and Xcode (11.3.1). I was able to get it to work by
In your Projects, select the target.
Goto General tab on top.
Under the 'Frameworks, Libraries and Embedded Content' section, add the framework (for me it was CoreNFC). Repeat for other targets.
Click on Build Phases on top and expand 'Link Binary with Libraries'.
Make the troublesome framework optional (from required).
This allowed me to compile for older/newer iPhones without making any code changes. I hope this helps other.
My environment: Cocos2d 2.0, Box2d, Objective C
In addition to doing the other answers above I finally went to the General tab and made WatchKit Optional.
In my case the solution was to remove the compiled framework from the Embedded Binaries, which was a standalone project in the workspace, clean and rebuild it, and finally re-add to Embedded Binaries.
If you are using a third-party framework, and using Cocoapods as your dependency manager, try doing a pod install to refresh your pods.
This crash was occurring on a third-party library I was using, so glad the above solution worked for me, hope it works for you!
Resolved for me by unselecting "Copy only when installed" on Build Phases->Embed Frameworks
I had the same issue. I tried building my project with an iPhone that I never used before and I didn't add a new framework. For me, cleaning up worked fine (Shift+Command+K). Maybe it's because I use beta 5 of Xcode 7 and an iPhone 6 with iOS 9 Beta, but it worked.
For any project or Framework project in Xcode that use pods, one easy way to avoid dynamic library (dylb) not to load is to set you pod file to ink in static mode. To do so, just make sure to don't write the following line in your pod file.
use_frameworks!
Once the line deleted from your file which you saved, simply run form the console:
$ pod update
In my case, my project is written by objective-c and in the library there are Swift files. So I changed "Always Embed Swift Standard Libraries" in my project’s Build Settings tab to Yes and it became totally okay.
If have development pod Delete your app from simulator install from pod -> clean - > run again...
The same thing was when I've created a new Configuration and Build Scheme.
So the solution for me was to run
pod install
for this newly created Configuration.
For me, I had to switch the XcodeKit.framework from "Do Not Embed" -> "Embed & Sign"
After trying all the methods available on internet and my own trial and error tricks 100 times. Finally I was able to solve it. – Apeksha Sahu 6 mins ago
Goto iTunes in Mac --> accounts-->Authorize this computer – Apeksha Sahu 5 mins ago
second step.... Goto developer in settings in iPad and iPhone and reindex with identifiers and clear trust computers everything. It worked for me........ ....... After reinstalling Mac OSHigh seria 10.13.15 version from Mac OS seirra beta latest version, to reinstalling Xcode latest version, after updating all certificates. etc etc etc... as many methods as you can think I did. –
Try with changing flag ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES (in earlier xcode versions: Embedded Content Contains Swift Code) in the Build Settings from NO to YES.
Xcode 11
Navigate to settings of your target and select General.
Look for "Frameworks, Libraries, and Embedded Content"
Keep "Do Not Embed" and make sure that all your targets (if you have more than one) have only set it's own framework and not others targets.
In Xcode 11
I was facing the same issue
Changing "Do Not Embed" in General Tab > "Frameworks, Libraries, and Embedded Content" was still resulting the same error.
What did solved for me was adding the Framework in Build Phases Tab > Embed Frameworks section
--Updated---
I observed that in projects built in previous versions of Xcode Embed Frameworks Section is not available when running in Xcode 11, Find the below steps to achieve the solution:
1: First need to add the New Copy Files Phase under Build Phases tab.
2: Second change the name of the added phase to Embed Frameworks
3: Change the destination to Frameworks.
4: Add the framework for which the error occurred.
Although everyone is saying to embed the framework under the Embedded Binaries but still it is not working, because we are missing one important step here.
Here are the two right steps to add the binaries under Embedded Binaries tab :
Remove the framework which is giving the error from the "Linked Frameworks and Libraries" under the General tab.
Now add the removed framework only under the Embedded Binaries tab and that is all one would need to do.
Run it on the device and keep that smile ;)
For SumUp Users, if you are loading the latest SumUpSDK.xcFramework, then you need to make sure that it's set to "Embed & Sign" from the application's General tab of the Target.
i.e. to reverse the above statement (making it easier to understand):
Go to the "Project Navigator" (i.e. the first icon to show all project items etc)
Select your project from the top of the tree.
On the menu in the middle of the page (slightly to the right), select your application under "Targets"
From the top-tab, select "General"
Scroll down to "Frameworks, Libraries and Embedded Content"
Select your Lib from the list
Select "Embed & Sign" from the drop down list next to it.
Clean
Re-Build and run.
I hope this helps.
H
Go to file in xcode -> Workspace settings
Click the arrow next to which appears /Users/apple/Library/Developer/Xcode/DerivedData
Select the Derived data and move it to Trash.
Quite the xcode and reopen it.
Clean the project and run again.
Above steps resolved my issuses.

Includes fail to resolve correctly in Xcode workspace

I'm having trouble linking to a static library in Xcode 5. I did read the chapter on building and using a static library in the Pro iOS 5 Tools. What it told me to do after creating your static library, was to link against the framework in the Build Phases tab. That part is pretty straight forward. Then it says in the Build Settings, under "Header Search Paths", to add:
$(BUILT_PRODUCTS_DIR)
Then in order to use my static library, I just import it like so:
#import "ConversionCalculator/ConversionCalculator.h"
So this used to work up until yesterday. I tried adding a new static library to my project which didn't seem to work. So I cleaned my project, and tried rebuilding again, but now Xcode complains about #import "ConversionCalculator/ConversionCalculator.h". It says
Lexical or Preprocessor issue. 'ConversionCalculator/ConversionCalculator.h' file could not be found.
I was wondering if anyone has any tips on debugging this. I've looked through different tutorials like this:
http://blog.stevex.net/2012/04/static-libraries-in-xcode/
http://cocoamanifest.net/articles/2011/06/library-management-with-xcode-workspaces.html
http://www.raywenderlich.com/41377/creating-a-status-library-in-ios-tutorial
But I can't seem to find the "golden way" to link to a static lib, or how to troubleshoot why Xcode cannot find my file. My file structure is setup on my machine like so:
Projects\
DistanceCalculator\DistanceCalculator.xcodeproj
ConversionCalculator\ConversionCalculator.xcodeproj
DistanceCalculator.workspace
Like I said, this all used to work too when I followed the tutorial in Pro iOS 5 Tools book. Now I don't know why my workspace cannot find ConversionCalculator when it has used it before. The part I find hard is different articles say different things about the header search path, and I'm not sure what the best way to populate that field is. Any thoughts? Thanks in advance!
Edit:
I'll add that I can build for the device without errors. But when I switch to the iPhone simulator, it gives me that error about not being able to find the file. I also see that I get this warning:
ConversionCalculator was rejected as an implicit dependency for 'libConversionCalculator.a' because its architectures 'i386' didn't contain all required architectures 'i386 x86_64'
Looking at that, I'm not sure what that means. If it means that my library is not being built for all architectures, I just tried creating a Target that builds for all architectures according to the wenderlich article in the above link. That seems to work as when I go to the dervieddata folder, I see for debug, release, and universal, I see the libConversionCalculator.a file. But then when I go back into the workspace and try to rebuild the project for the simulator, I get that could not find file error and the implicit warning.
Edit #2:
I just saw a warning flag on Xcode that says upgrade to recommended Build Settings. Now I get no errors. Not sure what happened... but I guess no errors is good.
I would follow the description available in Xcode's Help topic "Linking Against Your Library" in chapter Configuration Your Application in Introduction to Using Static Libraries in iOS
(you may search within Xcode Help, too).
Except that I would recommend to include your headers from libraries always using angle brackets:
#import <ConversionCalculator/ConversionCalculator.h>
Using double quotes may inadvertently search and find files with the same name in some sub-folder relative to the file where this import directive is written. Only after there was no file in any sub-folder the preprocessor starts searching with the specified header search paths.
Using angle brackets, the preprocessor immediately searches only at the specified header search paths.
So, since you actually want to find headers for the corresponding library, always use angle brackets.
Note: If you follow the recommendation to create a static library project, you don't need to explicitly set a header search path in the target that links agains the library: Xcode will already add a search path:
$(BUILT_PRODUCTS_DIR)/includes
Your library headers are located in
$(BUILT_PRODUCTS_DIR)/includes/<product-name>
which are placed there through the "Copy-Files" phase of the iOS static library target, whose "Destination" is set to "Products Directory" and whose "Subpath" is set to "includes/${PRODUCT_NAME}" per default.
You may change these default settings to other reasonable and sensible values. (if you do, consider the the consequences for Xcode's default search paths!)

Resources