この質問は、XCode 3に対して尋ねられたため、はるかに時代遅れです。XCode4以降では有用であるとは考えないでください。=）
私のアプリは（一見）ランダムなイベントでクラッシュします。そこで、iPhoneアプリケーションをデバッグするためにNSZombieEnabledを追加したいと思いました。ターゲットのクローンを作成し、そのInfo.plistを元のターゲットと同じに設定し、NSZombieEnabledをYESに設定しました。
アプリを実行すると、スタックトレースが...でクラッシュします。
#0 0x3025db0c in ___forwarding___ ()
#1 0x30239db2 in __forwarding_prep_0___ ()
#2 0x304f5105 in NSPopAutoreleasePool ()
#3 0x308ee452 in _UIApplicationHandleEvent ()
#4 0x32031425 in PurpleEventCallback ()
#5 0x30235253 in CFRunLoopRunSpecific ()
#6 0x302343c8 in CFRunLoopRunInMode ()
#7 0x308e6209 in -[UIApplication _run] ()
#8 0x308eef81 in UIApplicationMain ()
#9 0x000023ef in main (argc=1, argv=0xbffff0bc) at /Users/tomen/Documents/MIB-Sprint4/main.m:26
これは、NSZombieEnabledがYESに設定されている場合にのみ発生します。設定されていない場合、アプリは実行されるだけです（異なる時間にクラッシュします）
「-[_NSZombiemethodSignatureForSelector：]」などのブレークポイントを追加したかったのですが、デバッグ中に非アクティブになります。「シンボルを怠惰にロード」をオンまたはオフにして、両方の方法で試してみました。
また、〜/.gdbinitファイルをに設定しようとしました
fb -[NSException raise]
fb -[NSAssertionHandler handleFailureInFunction:file:lineNumber:description:]
fb -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:]
#define NSZombies
# this will give you help messages. Set to NO to turn them off.
set env MallocHelp=YES
# might also be set in launch arguments.
set env NSZombieEnabled=YES
set env NSDeallocateZombies=NO
set env MallocCheckHeapEach=100000
set env MallocCheckHeapStart=100000
set env MallocScribble=YES
set env MallocGuardEdges=YES
set env MallocCheckHeapAbort=1
set env CFZombie 5
fb -[_NSZombie init]
fb -[_NSZombie retainCount]
fb -[_NSZombie retain]
fb -[_NSZombie release]
fb -[_NSZombie autorelease]
fb -[_NSZombie methodSignatureForSelector:]
fb -[_NSZombie respondsToSelector:]
fb -[_NSZombie forwardInvocation:]
fb -[_NSZombie class]
fb -[_NSZombie dealloc]
fb szone_error
これにより、コンソールでこの結果が得られます。
The Debugger has exited with status 0.
[Session started at 2009-09-08 13:48:40 +0200.]
Loading program into debugger…
GNU gdb 6.3.50-20050815 (Apple version gdb-966) (Tue Mar 10 02:43:13 UTC 2009)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-apple-darwin".warning: Unable to read symbols for "/System/Library/Frameworks/UIKit.framework/UIKit" (file not found).
warning: Unable to read symbols from "UIKit" (not yet mapped into memory).
warning: Unable to read symbols for "/System/Library/Frameworks/CoreGraphics.framework/CoreGraphics" (file not found).
warning: Unable to read symbols from "CoreGraphics" (not yet mapped into memory).
Pending breakpoint 1 - "-[NSException raise]" resolved
Pending breakpoint 2 - "-[NSAssertionHandler handleFailureInFunction:file:lineNumber:description:]" resolved
Pending breakpoint 3 - "-[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:]" resolved
Pending breakpoint 14 - "szone_error" resolved
Program loaded.
sharedlibrary apply-load-rules all
Attaching to program: `/Users/tomen/Library/Application Support/iPhone Simulator/User/Applications/F77D9D82-0B34-4B8D-9076-AE883A2714F4/MIB.app/MIB', process 279.
Re-enabling shared library breakpoint 1
Re-enabling shared library breakpoint 2
Re-enabling shared library breakpoint 3
Re-enabling shared library breakpoint 14
Re-enabling shared library breakpoint 16
Re-enabling shared library breakpoint 17
Re-enabling shared library breakpoint 18
warning: Couldn't raise load state for requested objfile: "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation" for breakpoint 1/
warning: Couldn't raise load state for requested objfile: "/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation" for breakpoint 2/
warning: Couldn't raise load state for requested objfile: "/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation" for breakpoint 3/
ブレークポイントが非アクティブ化されるのはなぜですか？