How to enable NSZombie in Xcode?

Question

I have an app that is crashing with no error tracing. I can see part of what is going on if I debug, but can't figure out which object is "zombie-ing".

Does anybody know how to enable NSZombie in Xcode 4?

Answer 1

Environment variables are now part of the "scheme".

To edit the scheme and turn on zombies:

• In the "Product" menu, select "Edit Scheme".

• Go to the "Run Foo.app" stage in the left panel, and the "Arguments" tab on the right.

• Add NSZombieEnabled to the "Environment Variables" section and set the value to YES, as you could in Xcode 3.

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In Xcode 4.1 and above, there's also a checkbox on the "Diagnostics" tab of the "Run" stage to "Enable Zombie Objects".

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With Xcode 6.4:

Answer 2

I encountered the same problem with troubleshooting EXC_BAD_ACCESS and had hard time to find the setting with Xcode 4.2 (the latest one that comes with iOS5 SDK). Apple keeps on moving things and the settings are no longer where they used to be.

Fortunately, I've found it and it works for the device, not just Simulator. You need to open the Product menu in the Xcode, select Edit scheme and then choose the Diagnostics tab. There you have "Enable Zombie Objects". Once selected and run in debugger will point you to the double released object! Enjoy!

In short

Product->Edit Scheme->Diagnostics-> Click Enable Zombie Objects

Answer 3

Product > Profile will launch Instruments and then you there should be a "Trace Template" named "Zombies". However this trace template is only available if the current build destination is the simulator - it will not be available if you have the destination set to your iOS device.

Also another thing to note is that there is no actual Zombies instrument in the instrument library. The zombies trace template actually consists of the Allocations instrument with the "Enable NSZombie detection" launch configuration set.

Answer 4

It's a simple matter of setting an environment variable on your executable (NSZombieEnabled = YES), and then running/debugging your app as normal.If you message a zombie, your app will crash/break to debugger and NSLog a message for you.

For more information, check out this CocoaDev page: http://www.cocoadev.com/index.pl?NSZombieEnabled

Also, this process will become much easier with the release of 10.6 and the next versions of Xcode and Instruments. Just saying'. =)

Answer 5

Product > Profile will pop up Instruments. Select zombies from the panel and go nuts.

Answer 6

Go to Product - Scheme - edit scheme - Arguments - Environment Variables set NSZombieEnabled = YES

Answer 7

In xcode 4.2

Goto, Product -> edit scheme -> click Run yourappname.app -> Diagonostics -> Enable Zombie object.

Answer 8

Here's a video and explaination how to use Instruments and NSZombie to find and fix memory crashes on iOS: http://www.markj.net/iphone-memory-debug-nszombie/

Answer 9

As of Xcode 3.2.5 and Snow Leopard (Mac OS X 10.6), you can run your code through the Zombies instrument: Run > Run with Performance Tool > Zombies. That allows you to see particular objects and their retain counts on a timeline.

Answer 10

In Xcode 4.5.2 goto Product -> Edit Scheme -> and Under the Diagnostics tab check the check box in between Objective C and Enable Zombie Objects and Click on OK

Answer 11

To enable Zombie logging double-click the executable in the executables group of your Xcode project. At this point click the Arguments tab and in the Variables to be set in the environment: section, make a variable called NSZombieEnabled and set its value to YES.

Answer 12

In XCode 4.0: To detect NSZombie in Instruments, select the Simulator as your target (can't detect NSZomboe on device). Run Instruments (CMD+I) and select "Zombies" trace template. Enjoy.

Answer 13

In the preferences of your executable add the environment variable NSZombieEnabled and set the value to YES.

Answer 14

in ur XCODE (4.3) next the play button :) (run)

select : edit scheme

the scheme management window will open

click on the Arguments tab

you should see : 1- Arguments passed on launch 2- environment variables

inside the the (2- environment variables) place Name: NSZombieEnabled
Value: YES

And its done....

Answer 15

NSZombieEnabled is used for Debugging BAD_ACCESS,

enable the NSZombiesEnabled environment variable from Xcode’s schemes sheet.

Click on Product⇒Edit Scheme to open the sheet and set the Enable Zombie Objects check box

this video will help you to see what i'm trying to say.