[objective-c] How do I set up NSZombieEnabled in Xcode 4?

How do I set up NSZombieEnabled and CFZombieLevel for my executable in Xcode 4?

I find this alternative more convenient:

1. Click the "Run Button Dropdown"
2. From the list choose Profile
3. The program "Instruments" should open where you can also choose Zombies
4. Now you can interact with your app and try to cause the error
5. As soon as the error happens you should get a hint on when your object was released and therefore deallocated.

As soon as a zombie is detected you then get a neat "Zombie Stack" that shows you when the object in question was allocated and where it was retained or released:

Event Type    RefCt     Responsible Caller
Malloc            1     -[MyViewController loadData:]
Retain            2     -[MyDataManager initWithBaseURL:]
Release           1     -[MyDataManager initWithBaseURL:]
Release           0     -[MyViewController loadData:]
Zombie           -1     -[MyService prepareURLReuqest]

Advantages compared to using the diagnostic tab of the Xcode Schemes:

1. If you forget to uncheck the option in the diagnostic tab there no objects will be released from memory.

2. You get a more detailed stack that shows you in what methods your corrupt object was allocated / released or retained.

In Xcode 4.2

• Project Name/Edit Scheme/Diagnostics/
• Enable Zombie Objects check box
• You're done

In Xcode > 4.3:

You click on the scheme drop down bar -> edit scheme -> arguments tab and then add NSZombieEnabled in the Environment Variables column and YES in the value column.

Good Luck !!!

Jano's answer is the easiest way to find it.. another way would be if you click on the scheme drop down bar -> edit scheme -> arguments tab and then add NSZombieEnabled in the Environment Variables column and YES in the value column...

On In Xcode 7

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or select Edit Scheme from Product > Scheme Menu

select Enable Zombie Objects form the Diagnostics tab

As alternative, if you prefer .xcconfig files you can read this article https://therealbnut.wordpress.com/2012/01/01/setting-xcode-4-0-environment-variables-from-a-script/

Cocoa offers a cool feature which greatly enhances your capabilities to debug such situations. It is an environment variable which is called NSZombieEnabled, watch this video that explains setting up NSZombieEnabled in objective-C