Related
I recently archived and uploaded my app for release for the first time. However, now when I try to print to the debugger, nothing is appearing. Also, breakpoints are not being activated when I run the simulator.
I am using Xcode 7.3, the latest at the time of this writing. My app contains a keyboard extension. Neither are printing to the debugger or triggering breakpoints. The debugger pane is set to show "All Output".
As far as I can tell, it is still using the "Debug" scheme, I never manually changed it. Would it have changed when I archived and uploaded the .ipa to iTunes Connect? What would have changed?
With your suggestion, can you be thorough in your suggestion? I may not have enough experience with Xcode to understand immediately, so the more explanation the better.
Look at the "Run Scheme" for your Project (Product->Scheme->Edit Scheme or option-click on the Run button) and check the Build Configuration pulldown. Make sure that's Debug, not Release.
BTW, you can also tell what binary is actually getting run by running in the debugger, hit the Pause button, then in the Debugger Console, type:
(lldb) image list <AppName>
That will show the path to the binary that got loaded. If this is the Release version that should show up in the path and you'll know you are debugging the wrong configuration...
In archiving my app, Xcode combined the scheme of the Containing App and the Keyboard extension. As a result, the Containing App was the only selection possible when choosing a scheme and the output of the Keyboard Extension was no longer sent to the debugger.
In order to solve this, I selected "Product > Scheme > New Scheme..." and then selected my Keyboard Extension to be its own Scheme again. Once the Keyboard Extension was a scheme again, it was able to be selected as the target scheme to send output to the Debugger.
This question already has answers here:
Unable to run app in Simulator : An error was encountered while running (Domain = LaunchServicesError, Code = 0)
(19 answers)
Closed 5 years ago.
I received an error (Domain = LaunchServicesError, Code = 0) when trying to launch my app in the iOS Simulator with Xcode 6. I looked for solution in google, but I didn't find anything practical.
What does this error mean?
This error indicates that there was a problem with installation. Unfortunately, Xcode does not actually print the contents of the error message that would give you more insight, but you can look at ~/Library/Logs/CoreSimulator/CoreSimulator.log to see the rest of the error details. There will also be more information about the problem in the simulated device's system log (~/Library/Logs/CoreSimulator/[Device UDID]/system.log); look for messages from installd around the time of the error).
Common causes for this include bundles missing an Info.plist, missing keys within your bundle's Info.plist, or values for some keys in the Info.plist not being allowed.
If your app's Info.plist does not contain a valid CFBundleVersion key/value pair, it is possible that your app may install correctly the first time but fail to update. Many users seem to work around this by doing a "Reset Contents & Settings" after each install, but it would be better to fix the root cause by setting an appropriate CFBundleVersion in the Info.plist. I believe iOS 8.2 now correctly returns an error on the first install in this case rather than just on updates, so hopefully this problem will be more obvious now.
Users with home directories on file systems that do not support hard links (eg: network home directories via AFP, SMB, or some NFS servers) may also run into problems related to hard linking. If this is the case, I suggest you create a path on your local HFS+ filesystem for simulator development (eg: /var/simulator/[user]) and create a symlink to that path from ~/Library/Developer/CoreSimulator. This particular issue was fixed in one of the iOS 8.2 betas.
In another case, the Build&Run would always succeed on the first try, but subsequent attempts would sometimes fail due to a changed Info.plist (eg: because someone's build system settings result in CFBundleVersion being different on each iteration). You can usually recover by either deleting the installed app (using a long-press from the home screen or xcrun simctl uninstall [Device UDID] [app identifier]) or erasing the device back to a default state. To erase the device, execute xcrun simctl erase [Device UDID] from terminal or choose Erase Contents & Settings from the iOS Simulator menu. This particular issue was fixed in one of the iOS 8.2 betas.
A newer instance of this issue is occurring for Xcode 6.2 users. If you have a WatchKit App Extension bundled in your app, it will fail to install to versions of the iOS Simulator runtime older than iOS 8.2. As a workaround, you will need to manually disable the app extension from installing when you want to test with iOS 8.1 and earlier runtimes.
If you need more specific help, please provide the entirety of the error message from CoreSimulator.log and any messages from installd and CoreSimulatorBridge that appear around the same time in ~/Library/Logs/CoreSimulator/[Device UDID]/system.log as that will reveal the underlying problem.
Does your project include a widget or extension? If so, the problem could be the bundle identifier of your widget/extension. It should be the same as the main target, appended with a period and an extra string. So for example:
Main target: com.mycompany.myapp
Widget should be: com.mycompany.myapp.widget
I fixed it by resetting the simulator:
iOS Simulator > Reset Contents and Settings...
Since everyone writes what they went through and how they fixed their exact problem, that might be unhelpful.
The problem is that there are different causes for the same error message and the right way of solving it is to open up ~/Library/Logs/CoreSimulator/CoreSimulator.log and look in there for the last message. This message gives you a good clue and sets you on the right path of solving your problem (sometimes it's bundle IDs, sometimes it's a missing or an extra attribute in the Info.plist, but you always get a good, descriptive clue).
This is how you narrow down the problem and eventually get to fix it.
Good luck and tough nerves with Xcode .)
Z.
For me I just cleaned the project and it worked -> Product -> Clean
TLDR: Clear your Project Build Folder - and you will be free of this pain.
( plus I logged this as a bug with Apple as they need to find a way to fix this in Xcode )
None of these solutions worked for me - I banged my head against several walls.
I looked at the CoreSimulator log and I realised that it was trying to build a library that I had deleted.
I couldn't find references to it anywhere.
Then I saw via another SO Question which unfortunately I can't find to reference, if you:
Hold down your option key then Product-> Clean option becomes Clean
Build Folder
Press that and enjoy having your error vanish
"Reset Content and Settings" from iOS Simutalor menu options and launching simulator after Quitting solved my issue.
In XCode 6
An error was encountered while running (Domain = LaunchServicesError,
Code = 0)
I had this error after making some major code changes to accommodate the iPhone 6 Screens. in Xcode 6 (iOS8)
I followed the options above and found that the only way to really get this fixed was by doing the following:
Deleted the derived data [go to Window >> Organizer >> (Find your App) Click on Delete next to the Derived Data]
Product >> Clean
Reset Contents and Settings in Simulator
Changed the Bundle Version to 1.4.1 from 1.4 in pList
Thank you for all the previous answers that got me to this stage. It worked a charm!
In my case, the error was caused because i didn't set the build id.
Setting this, launches the emulator without problem.
One other thing to try, that worked for me, after resetting the simulator and doing a clean build did not help, is clearing out the derived data. To do this: go to Organizer click on project click on delete derived data button. I had this happen after working on an extension for a while and went back to the regular branch. Hope this helps.
This is what caused the problem for me: the build number for the main app and the extension were different (I had incremented the main app build number to 1.0.1.03, but left the extension at 1.0.1.02).
Making them match fixed the problem for me.
Open the Console app and look there. In my case it told me exactly what to do. I saw:
ErrorDescription=WatchKit 2 app extension's NSExtension.NSExtensionAttributes.WKAppBundleIdentifier value does not match WatchKit app's bundle ID (found "com.myCompany.MyApp.MyApp.watchkitapp"; expected "com.myCompany.MyApp.watchkitapp").
So, I went to each plist and checked any items that related to a BundleID. Then Clean, relaunch, etc.
My case was about framework compilation. I have enabled the 'copy only when installing' option from Target- Build Phases- Embedded Frameworks-
I have an app that is set up to use different bundle IDs based on the build configuration. When creating my Apple Watch extension, Xcode generated everything using my Release ID, so I had to go through and change it all manually for debugging. Here's all the places I had to change it:
WatchKit Extension's Build Settings -> Packaging -> Product Bundle Identifier
WatchKit Extension's Info.plist -> NSExtension -> NSExtensionAttributes -> WKAppBundleIdentifier (this needs to use the same prefix as your companion app)
WatchKit App's Info.plist -> WKCompanionAppBundleIdentifier
The last one took me a while since the WatchKit App's Info doesn't show up as a tab when viewing the target settings, I had to go direct to the Info.plist file itself.
Try putting some number into [TARGETS]-[General]-[Identity]-[Version(or Build)], if they are empty.
It worked for me.
I hope it will help you.
I also have this error. In my case the log ~/Library/Logs/CoreSimulator/CoreSimulator.log was something like that :
Could not hardlink copy /Users/myUser/Library/Developer/CoreSimulator/Devices/60E569E7-6750-428A-A401-841BB081xxxx/data/Containers/Bundle/Application/70F24DDC-7954-46BF-B799-F807FD98yyyy/myApp.app to /Users/myUser/Library/Developer/CoreSimulator/Devices/60E569E7-6750-428A-A401-841BB081xxxx/data/Library/Caches/com.apple.mobile.installd.staging/temp.kOrJ9G/extracted/Payload/myApp.app with manifest /Users/myUser/Library/Developer/CoreSimulator/Devices/60E569E7-6750-428A-A401-841BB081xxxx/data/Library/Caches/com.apple.mobile.installd.staging/temp.kOrJ9G/extracted/com.apple.deltainstallcommands.com.mycompagny.myapp
thanks to this answer In look at my app info.plist. the key CFBundleVersion was missing so I add it and now everything is working !
None of the above worked for me, but this did:
I simply deleted IceCream.xcworkspace/xcuserdata/xcuserdatad and then reset the simulator and ran the app again. (Reseting the simulator alone, did not work for me.)
"Reset Content and Settings" from iOS Simutalor menu options and launching simulator after Quitting solved my issue.
The great explanation by Jeremy at least set me in the right direction, but despite having all the bundle identifiers and versions set correctly, the error still persisted. I then checked the Apple documentation which shows that the WatchKit extension (in its Copy Bundle Resources phase) copies the WatchKit app. This WatchKit app was named exactly the same as my iOS app, causing Xcode to confuse the two and read out the wrong plist, thinking the bundle identifier was incorrect. Renaming the Product of the WatchKit app to something distinct finally solved it for me.
If you've changed your bundle ID, make sure you do a clean build before trying to build it again! See how here: How to Empty Caches and Clean All Targets Xcode 4
So it's definitelly .plist problem. In my case it was empty NSExtensionMainStoryboard, removing this property fixed the problem
I had this error whilst trying to build Apple's Lister Xcode Project and run it on the simulator.
The essentials which fixed it for me were:
1) BundleID for the iOS App and the iOS Extension had to be different
2) I provide iCloud and App Groups for both targets
3) I used Xcode's "Fix Issue" to fix the issues
After that I could build and run the app without warnings or errors.
The clue from the log file was "... LegacyErrorString=DuplicateIdentifier, FunctionName=-[MIInstallableBundle performPreflightWithError:], SourceFileLine=450, NSLocalizedDescription=The parent bundle has the same identifier (com.ACMECompany.Lister) as sub-bundle at /Users/stephen/Library/Developer/CoreSimulator/Devices/5329928B-946B-40A4-B666-EFD11B96D11F/data/Library/Caches/com.apple.mobile.installd.staging/temp.HQ5d9X/extracted/Lister.app/PlugIns/Lister.appex"
Had a wrong app version set in InfoPlist.strings localization file. Urgh!
An hour gone!
Delete your simulator and regenerate one.
It works for me.
I removed the key in watch app's .plist file that shouldn't have been there. And the problem disappeared.
This worked for me:
In project settings -> General tab -> Identity section I changed the Version number from something like 2.0.2 (three digits) to 2.0 (two digits) then I deleted the app in the simulator and run the project again. No more error after that.
One other possible solution to add to all of the others that will no doubt stay above mine ;)
I deleted & later reinstated a Today Extension target retaining the source files, but after trying every solution under the sun, I realised it didn't have any sources or resources in its target! You might encounter this as well if your detailed launch services error can't find your compiled app extension file.
So, long story short, make sure your target has something included to compile or bundle in there. You can check your target memberships by selecting the relevant file(s) on your project navigator (on the left) and setting your checkmark(s) as appropriate in the file inspector (that's the first tab on the right).
I had the following in my log...
<Error>: Error Domain=LaunchServicesError Code=0 "(null)" UserInfo={Error=ExecutableTwiddleFailed...
This was due to there being no source files added in the extension project.
This error was showing up on my system when there was no hard disk space available. I freed up some space on my system for it to work.
My Problem was that the wrapper extension for the target project was unset.
To fix I had to go to target project -> build settings -> Packaging -> Wrapper Extension.
Set this to "app" (No quotes)
This fixed the problem for me
I'm trying to debug the sample Action App Extension provided on Xcode 6 (6A313).
Even though the app runs flawlessly, I can't see any NSLog messages on the Debug Area neither Xcode will stop on my break points.
Things I've tried:
I've tried uninstalling Xcode 6, re-downloading it from the Mac Store and installing again with no success.
I've also tried to go through Debug -> Attach to Process -> By Process Identifier (PID) or Name... but the Status Bar shows "Waiting for -bundle id- to launch" when it is already running.
Tried different devices.
Tried running on the simulator, but my App Extension won't show on the App Extensions list (it is not present in the "more" list also).
I've checked this answer also, which didn't help me.
I've ran out of ideas on what to do :)
When you added the Application Extension target Xcode should have added also a new Scheme for the Extension (or you can create one in 'Manage Schemes...').
If this happened you just have to change the Active Scheme, on the very left of the drop down with which you choose the device/os of the simulator, and run.
If you change the Active Scheme to the Widget one, then breakpoint and NSLog works, at least for me.
This question already has answers here:
Unable to run app in Simulator : An error was encountered while running (Domain = LaunchServicesError, Code = 0)
(19 answers)
Closed 5 years ago.
I received an error (Domain = LaunchServicesError, Code = 0) when trying to launch my app in the iOS Simulator with Xcode 6. I looked for solution in google, but I didn't find anything practical.
What does this error mean?
This error indicates that there was a problem with installation. Unfortunately, Xcode does not actually print the contents of the error message that would give you more insight, but you can look at ~/Library/Logs/CoreSimulator/CoreSimulator.log to see the rest of the error details. There will also be more information about the problem in the simulated device's system log (~/Library/Logs/CoreSimulator/[Device UDID]/system.log); look for messages from installd around the time of the error).
Common causes for this include bundles missing an Info.plist, missing keys within your bundle's Info.plist, or values for some keys in the Info.plist not being allowed.
If your app's Info.plist does not contain a valid CFBundleVersion key/value pair, it is possible that your app may install correctly the first time but fail to update. Many users seem to work around this by doing a "Reset Contents & Settings" after each install, but it would be better to fix the root cause by setting an appropriate CFBundleVersion in the Info.plist. I believe iOS 8.2 now correctly returns an error on the first install in this case rather than just on updates, so hopefully this problem will be more obvious now.
Users with home directories on file systems that do not support hard links (eg: network home directories via AFP, SMB, or some NFS servers) may also run into problems related to hard linking. If this is the case, I suggest you create a path on your local HFS+ filesystem for simulator development (eg: /var/simulator/[user]) and create a symlink to that path from ~/Library/Developer/CoreSimulator. This particular issue was fixed in one of the iOS 8.2 betas.
In another case, the Build&Run would always succeed on the first try, but subsequent attempts would sometimes fail due to a changed Info.plist (eg: because someone's build system settings result in CFBundleVersion being different on each iteration). You can usually recover by either deleting the installed app (using a long-press from the home screen or xcrun simctl uninstall [Device UDID] [app identifier]) or erasing the device back to a default state. To erase the device, execute xcrun simctl erase [Device UDID] from terminal or choose Erase Contents & Settings from the iOS Simulator menu. This particular issue was fixed in one of the iOS 8.2 betas.
A newer instance of this issue is occurring for Xcode 6.2 users. If you have a WatchKit App Extension bundled in your app, it will fail to install to versions of the iOS Simulator runtime older than iOS 8.2. As a workaround, you will need to manually disable the app extension from installing when you want to test with iOS 8.1 and earlier runtimes.
If you need more specific help, please provide the entirety of the error message from CoreSimulator.log and any messages from installd and CoreSimulatorBridge that appear around the same time in ~/Library/Logs/CoreSimulator/[Device UDID]/system.log as that will reveal the underlying problem.
Does your project include a widget or extension? If so, the problem could be the bundle identifier of your widget/extension. It should be the same as the main target, appended with a period and an extra string. So for example:
Main target: com.mycompany.myapp
Widget should be: com.mycompany.myapp.widget
I fixed it by resetting the simulator:
iOS Simulator > Reset Contents and Settings...
Since everyone writes what they went through and how they fixed their exact problem, that might be unhelpful.
The problem is that there are different causes for the same error message and the right way of solving it is to open up ~/Library/Logs/CoreSimulator/CoreSimulator.log and look in there for the last message. This message gives you a good clue and sets you on the right path of solving your problem (sometimes it's bundle IDs, sometimes it's a missing or an extra attribute in the Info.plist, but you always get a good, descriptive clue).
This is how you narrow down the problem and eventually get to fix it.
Good luck and tough nerves with Xcode .)
Z.
For me I just cleaned the project and it worked -> Product -> Clean
TLDR: Clear your Project Build Folder - and you will be free of this pain.
( plus I logged this as a bug with Apple as they need to find a way to fix this in Xcode )
None of these solutions worked for me - I banged my head against several walls.
I looked at the CoreSimulator log and I realised that it was trying to build a library that I had deleted.
I couldn't find references to it anywhere.
Then I saw via another SO Question which unfortunately I can't find to reference, if you:
Hold down your option key then Product-> Clean option becomes Clean
Build Folder
Press that and enjoy having your error vanish
"Reset Content and Settings" from iOS Simutalor menu options and launching simulator after Quitting solved my issue.
In XCode 6
An error was encountered while running (Domain = LaunchServicesError,
Code = 0)
I had this error after making some major code changes to accommodate the iPhone 6 Screens. in Xcode 6 (iOS8)
I followed the options above and found that the only way to really get this fixed was by doing the following:
Deleted the derived data [go to Window >> Organizer >> (Find your App) Click on Delete next to the Derived Data]
Product >> Clean
Reset Contents and Settings in Simulator
Changed the Bundle Version to 1.4.1 from 1.4 in pList
Thank you for all the previous answers that got me to this stage. It worked a charm!
In my case, the error was caused because i didn't set the build id.
Setting this, launches the emulator without problem.
One other thing to try, that worked for me, after resetting the simulator and doing a clean build did not help, is clearing out the derived data. To do this: go to Organizer click on project click on delete derived data button. I had this happen after working on an extension for a while and went back to the regular branch. Hope this helps.
This is what caused the problem for me: the build number for the main app and the extension were different (I had incremented the main app build number to 1.0.1.03, but left the extension at 1.0.1.02).
Making them match fixed the problem for me.
Open the Console app and look there. In my case it told me exactly what to do. I saw:
ErrorDescription=WatchKit 2 app extension's NSExtension.NSExtensionAttributes.WKAppBundleIdentifier value does not match WatchKit app's bundle ID (found "com.myCompany.MyApp.MyApp.watchkitapp"; expected "com.myCompany.MyApp.watchkitapp").
So, I went to each plist and checked any items that related to a BundleID. Then Clean, relaunch, etc.
My case was about framework compilation. I have enabled the 'copy only when installing' option from Target- Build Phases- Embedded Frameworks-
I have an app that is set up to use different bundle IDs based on the build configuration. When creating my Apple Watch extension, Xcode generated everything using my Release ID, so I had to go through and change it all manually for debugging. Here's all the places I had to change it:
WatchKit Extension's Build Settings -> Packaging -> Product Bundle Identifier
WatchKit Extension's Info.plist -> NSExtension -> NSExtensionAttributes -> WKAppBundleIdentifier (this needs to use the same prefix as your companion app)
WatchKit App's Info.plist -> WKCompanionAppBundleIdentifier
The last one took me a while since the WatchKit App's Info doesn't show up as a tab when viewing the target settings, I had to go direct to the Info.plist file itself.
Try putting some number into [TARGETS]-[General]-[Identity]-[Version(or Build)], if they are empty.
It worked for me.
I hope it will help you.
I also have this error. In my case the log ~/Library/Logs/CoreSimulator/CoreSimulator.log was something like that :
Could not hardlink copy /Users/myUser/Library/Developer/CoreSimulator/Devices/60E569E7-6750-428A-A401-841BB081xxxx/data/Containers/Bundle/Application/70F24DDC-7954-46BF-B799-F807FD98yyyy/myApp.app to /Users/myUser/Library/Developer/CoreSimulator/Devices/60E569E7-6750-428A-A401-841BB081xxxx/data/Library/Caches/com.apple.mobile.installd.staging/temp.kOrJ9G/extracted/Payload/myApp.app with manifest /Users/myUser/Library/Developer/CoreSimulator/Devices/60E569E7-6750-428A-A401-841BB081xxxx/data/Library/Caches/com.apple.mobile.installd.staging/temp.kOrJ9G/extracted/com.apple.deltainstallcommands.com.mycompagny.myapp
thanks to this answer In look at my app info.plist. the key CFBundleVersion was missing so I add it and now everything is working !
None of the above worked for me, but this did:
I simply deleted IceCream.xcworkspace/xcuserdata/xcuserdatad and then reset the simulator and ran the app again. (Reseting the simulator alone, did not work for me.)
"Reset Content and Settings" from iOS Simutalor menu options and launching simulator after Quitting solved my issue.
The great explanation by Jeremy at least set me in the right direction, but despite having all the bundle identifiers and versions set correctly, the error still persisted. I then checked the Apple documentation which shows that the WatchKit extension (in its Copy Bundle Resources phase) copies the WatchKit app. This WatchKit app was named exactly the same as my iOS app, causing Xcode to confuse the two and read out the wrong plist, thinking the bundle identifier was incorrect. Renaming the Product of the WatchKit app to something distinct finally solved it for me.
If you've changed your bundle ID, make sure you do a clean build before trying to build it again! See how here: How to Empty Caches and Clean All Targets Xcode 4
So it's definitelly .plist problem. In my case it was empty NSExtensionMainStoryboard, removing this property fixed the problem
I had this error whilst trying to build Apple's Lister Xcode Project and run it on the simulator.
The essentials which fixed it for me were:
1) BundleID for the iOS App and the iOS Extension had to be different
2) I provide iCloud and App Groups for both targets
3) I used Xcode's "Fix Issue" to fix the issues
After that I could build and run the app without warnings or errors.
The clue from the log file was "... LegacyErrorString=DuplicateIdentifier, FunctionName=-[MIInstallableBundle performPreflightWithError:], SourceFileLine=450, NSLocalizedDescription=The parent bundle has the same identifier (com.ACMECompany.Lister) as sub-bundle at /Users/stephen/Library/Developer/CoreSimulator/Devices/5329928B-946B-40A4-B666-EFD11B96D11F/data/Library/Caches/com.apple.mobile.installd.staging/temp.HQ5d9X/extracted/Lister.app/PlugIns/Lister.appex"
Had a wrong app version set in InfoPlist.strings localization file. Urgh!
An hour gone!
Delete your simulator and regenerate one.
It works for me.
I removed the key in watch app's .plist file that shouldn't have been there. And the problem disappeared.
This worked for me:
In project settings -> General tab -> Identity section I changed the Version number from something like 2.0.2 (three digits) to 2.0 (two digits) then I deleted the app in the simulator and run the project again. No more error after that.
One other possible solution to add to all of the others that will no doubt stay above mine ;)
I deleted & later reinstated a Today Extension target retaining the source files, but after trying every solution under the sun, I realised it didn't have any sources or resources in its target! You might encounter this as well if your detailed launch services error can't find your compiled app extension file.
So, long story short, make sure your target has something included to compile or bundle in there. You can check your target memberships by selecting the relevant file(s) on your project navigator (on the left) and setting your checkmark(s) as appropriate in the file inspector (that's the first tab on the right).
I had the following in my log...
<Error>: Error Domain=LaunchServicesError Code=0 "(null)" UserInfo={Error=ExecutableTwiddleFailed...
This was due to there being no source files added in the extension project.
This error was showing up on my system when there was no hard disk space available. I freed up some space on my system for it to work.
My Problem was that the wrapper extension for the target project was unset.
To fix I had to go to target project -> build settings -> Packaging -> Wrapper Extension.
Set this to "app" (No quotes)
This fixed the problem for me
- (void)viewDidLoad
{
NSLog(#"%s", __func__);
// ...
}
in viewDidLoad of an iOS 8 extension. the NSLog outputs nothing in Xcode. NSLog works as usual in the container app though.
How can I get output from debug messages from an extension?
Debugging works for app extensions.
It works on simulator too.
If your app ext crashes in the simulator, you may find it is not easy to restart your app ext. Restarting your simulator is a quick solution.
Steps to debug an app extension:
Run the container app. In this step, Xcode uploads the container app and app extension to the device or simulator.
Stop the container app. This step is important when you debug in simulator. If you don't do it, Xcode will tell you the simulator is in use.
In Xcode, press menu Debug -> Attach to Process -> By Process Identifer (PID) or Name..., input the app ext's identifier, e.g. com.abc.ContainerApp.MyExtension, to start debugging. Don't forget to set break points. (Update on Aug 25, 2014: you can input MyExtension(your extension's name) directly.)
In the device or simulator, open your app extension.
Updates on Aug 23, 2014:
I found the debugging steps above do not work well on Xcode 6 beta 6 with iOS 8 SDK beta 5 on the simulator.
Solution:
Run your extension in the simulator.
Xcode menu Debug -> Attach to Process -> Choose "MyExtension(your extension's name)" in System section in the menu.
The breakpoints work. But I don't know why logs do not show in the output window.
I'm having this problem too. It works for me if you go in your Simulator under the menu Debug -> Open System Log...
From here you can see all the logs of the iPhone Simulator (included your extension's logs).
NSLog is working perfectly.
You just don't see what is being logged in the debug area of Xcode because the Xcode debugger isn't attached to your extension. Extensions are nearly completely independent from their containing app. They have separate bundle identifiers, for example, and they also are separate processes on the OS.
I have had varied success in getting Xcode to attach to extensions. Supposedly it seems it would attach automatically, and it appears in the debug navigator as "Waiting to attach", but never attaches.
Sometimes, I am able to run my extension target in Xcode:
And then have the option to choose what application to run my extension in. In this case, I would choose its recommendation of "today", which is notification center.
And then it would sometimes attach the debugger to my extension. Note this method only works on physical devices, it seems.
If it doesn't attach you can use the manual attachment method in #VinceYaun's answer,
I have also had varied success using other methods of attachment. Most have been unsuccessful, and it seems they are just bugs that will be fixed at a later date.
To view your log messages you go to Window -> Devices in the top bar and select your device. You can bring up the device log from the bottom of that window. If you are testing on a simulator, you can use #BalestraPatrick's answer.
Some of the bugs have been fixed in Beta 2, and my guess is that eventually the debugger will attach automagically when launching the extension.
Update: In the iOS 8 Beta 4 release notes:
Extensions
Fixed in beta 4
Extensions sometimes fail to launch when debugging from Xcode.
When Extension with UI is killed, it relaunches and is not dismissed.
Sometimes your Sharing or Action extension can hang.
Redeploying an extension may disable it in Notification Center.
I'm having this problem too. Xcode never attaches my debugger to the extension or displays NSLog messages. If you attach your Xcode debugger manually to your extension process, at least breakpoints work like a charm:
Debug->Attach to process->Your extension name (mine was "com.example.MyExtensionApp.MyExtension")
Create scheme for your extension
Run scheme
In a dialog choose container app
Enjoy
It works for me :)
Xcode 8 is able to debug extensions:
Choose the extension scheme in the combo next to the stop button and run it.
Select the parent application in the dialog that appears.
Result: breakpoints and log work as usual.
What finally allowed me to see the log in the debugging area, based on Michael's suggestion and Apple's documentation, is:
Build & Run the app extension in the simulator and, when prompted for a host app, choose the specific app that you're going to call the extension from. In my case I was launching my Action extension from Safari by pulling up a share sheet on a PDF.
What wasn't working before was following other people's suggestions of using Today as the host but then leaving that app and going over to Safari to call my extension. I no longer even need to run my containing app first before running the extension.
From Apple's Documentation:
In your extension scheme’s Run phase, you specify a host app as the executable. Upon accessing the extension through that specified host’s UI, the Xcode debugger attaches to the extension.
I actually got the logs to run quite simply in Xcode 6.3. Firstly, build and run the containing app. Once the containing app is running on the device, build and run the app extension by changing the scheme to the app extension.
Apple has documentation directly related to debugging, profiling and testing your app extension.
A trick which works for me (although it is quite an ugly one) is to place a dummy UILabel somewhere in the bottom corner of my extension. I usually call it logLabel. It is then possible to update the text of this label with any log statement that you want to get logged. Such approach is not very good if you need to log statements from instances of different classes. And, obviously, it clutters your UI.
However, if you have a fairly simple widget and you don't mind about slight cluttering of the UI this does the trick. I have tried all other solutions outlined in this discussion and, sadly, none of them worked for me.
The only way debugging works for me is by selecting Debug->Attach To Process By PID or Name
Then enter the PID not the extension name.
You can find the PID by running the extension on a device, go to Window->Devices. Find your device and viewing the console. When you see the name of your extension, its followed by 5 digit number. That is the PID
I also put a bunch of NSLog's in the extension in order to find the PID as well.
This is on xCode 7
Encounter the same problem about extension for NSLog, and break points. I have fought it with many days.
Device log can be found as following image. It is at XCode -> Window -> Devices and Simulators.
After enter the Open Console, there is a search field at the top-right of dialog. I can apply filter rule in there. For example, a process name contains Notification key word, or process name must equal to the name of extension target, ex: equal to MyNotificationServiceExtension process name.
Clearly something is broken in Xcode6-B5.
If I try to run a Photo extension on the Simulator I cannot see any Photos.app as an option for the extension attaching process.
The same, running on a real device, give me the correct behaviour.
In the first case any breakpoint is not honorated. In the latter case, breakpoints work like a charm.
You should know that the container app and extension are totally two difference process in iOS while the LLVM debugs only a thread a time, so when you are debugging, the console never log the extension and never stop at breakpoint.
You can solve most of the problems by #Vince Yuan's method.
However, my problem is that Xcode debugger hardly hook on my keyboard extension on both iOS Simulator and devices, like 1 time in 7-8 runs, It's totally a matter of probability. #Vince Yuan's method also work for just sometimes.
My little experience is that when you run you debug scheme, if the debug Session in the left panel showing that 'No Debug Session', there is no need to open your extension and test it, the debugger didn't hook on, just run again for lucky.
but when you see com.xxx.xxx.xxx is waiting to Attach, the extension can definitely get debugged.
This is a little trick for whom cannot debug iOS extension, especially keyboard extension.
As of Xcode 6 Beta 5, I've been able to use an actual device running iOS8 to debug my extension. Try running it on a device and select Safari to launch into
To overcome all the states caused by ever changing IDE, I'm using iOS Console by lemonjar.com – it displays a console window for any connected iOS device rendering syslog messages regardless the process ID. You can see both app and extension debug log messages at once here.
I could debug my extension with the way I describe below:
Xcode : Debug -> Attach to process by PID or Name. Your extension scheme name.
Then select your main app target and run.
I hope it also works for you guys.