# Advanced Apple Debugging **URL:** https://forums.kodeco.com/c/books/advanced-apple-debugging/31.md [Latest](https://forums.kodeco.com/latest.md) · [Categories](https://forums.kodeco.com/categories.md) · [Tags](https://forums.kodeco.com/tags.md) --- ## [About the Advanced Apple Debugging category](https://forums.kodeco.com/t/about-the-advanced-apple-debugging-category/27904)
**Author:** [@crispy8888](https://forums.kodeco.com/u/crispy8888)\ **Replies:** 2\ **Last updated:** [June 11, 2022, 6:01am UTC](https://forums.kodeco.com/t/about-the-advanced-apple-debugging-category/27904 "2022-06-11T06:01:22Z")
For anything and everything related to the book Advanced Apple Debugging & Reverse Engineering, available here: Advanced Apple Debugging & Reverse Engineering | Kodeco --- ## [P command no longer assigns to a variable](https://forums.kodeco.com/t/p-command-no-longer-assigns-to-a-variable/214454)
**Author:** [@theng](https://forums.kodeco.com/u/theng)\ **Replies:** 1\ **Last updated:** [June 9, 2026, 4:03pm UTC](https://forums.kodeco.com/t/p-command-no-longer-assigns-to-a-variable/214454 "2026-06-09T16:03:48Z")
I’m on chapter 5 page 98, when running the p self command it no longer seems to assign the resulting object to a variable. This is in Xcode 26, is there a setting to reenable this behaviour? --- ## [Chapter 1, Swift vs Objective-C Debugging expression issue](https://forums.kodeco.com/t/chapter-1-swift-vs-objective-c-debugging-expression-issue/213799)
**Author:** [@chucky6](https://forums.kodeco.com/u/chucky6)\ **Replies:** 2\ **Last updated:** [January 22, 2026, 12:18pm UTC](https://forums.kodeco.com/t/chapter-1-swift-vs-objective-c-debugging-expression-issue/213799 "2026-01-22T12:18:19Z")
I followed this example as written and ran into an issue, but I believe I found the cause. The correct command appears to be expr -l swift -- import Foundation, not ex -l swift -- import Foundation as shown in the book. … --- ## [Chapter 4: Stopping in Code. Breakpoint Actions](https://forums.kodeco.com/t/chapter-4-stopping-in-code-breakpoint-actions/211887)
**Author:** [@algashev](https://forums.kodeco.com/u/algashev)\ **Replies:** 3\ **Last updated:** [January 14, 2026, 4:14pm UTC](https://forums.kodeco.com/t/chapter-4-stopping-in-code-breakpoint-actions/211887 "2026-01-14T16:14:09Z")
(lldb) breakpoint set -n "-\[UIViewController viewDidLoad\]" -C "po $arg1" -G1 Xcode 16.2 (16C5032a) does not print anything in console. It only works if you use manual input through the Breakpoint Navigator with «Debugg… --- ## [Chapter 18, 4th ed: Missing sections and stuff](https://forums.kodeco.com/t/chapter-18-4th-ed-missing-sections-and-stuff/213721)
**Author:** [@ibum](https://forums.kodeco.com/u/ibum)\ **Replies:** 0\ **Last updated:** [November 14, 2025, 5:20am UTC](https://forums.kodeco.com/t/chapter-18-4th-ed-missing-sections-and-stuff/213721 "2025-11-14T05:20:33Z")
Xcode 26. No more \_\_TEXT.\_\_objc\_methname section no “Unexpectedly found nil while unwrapping an Optional value” string no \_\_DATA\_CONST.\_\_objc\_classlist section no arc4random\_uniform fixup These 2 last absences rende… --- ## [Chapter 13 – Missing Dumped Symbols](https://forums.kodeco.com/t/chapter-13-missing-dumped-symbols/211501)
**Author:** [@zeppin](https://forums.kodeco.com/u/zeppin)\ **Replies:** 0\ **Last updated:** [June 22, 2025, 8:10am UTC](https://forums.kodeco.com/t/chapter-13-missing-dumped-symbols/211501 "2025-06-22T08:10:38Z")
Let me start by saying how much I’m enjoying this book. I’m on Chapter 13 and have encountered an issue with dumping the symbols for the executeLotsOfArguments method. Specifically when I run the lldb command image dum… --- ## [Chapter 11: Rewriting an Objective-C constant string requires CFStringCreateWithBytes](https://forums.kodeco.com/t/chapter-11-rewriting-an-objective-c-constant-string-requires-cfstringcreatewithbytes/210793)
**Author:** [@grittytree0163](https://forums.kodeco.com/u/grittytree0163)\ **Replies:** 1\ **Last updated:** [June 17, 2025, 5:35am UTC](https://forums.kodeco.com/t/chapter-11-rewriting-an-objective-c-constant-string-requires-cfstringcreatewithbytes/210793 "2025-06-17T05:35:54Z")
In chapter 11 \> Changing Around Values in Registers When I write p/x @“Yay! Debugging”, i got below error: error: Error \[IRForTarget\]: Rewriting an Objective-C constant string requires CFStringCreateWithBytes Can … --- ## [Broken link in Chapter 25](https://forums.kodeco.com/t/broken-link-in-chapter-25/206416)
**Author:** [@elliotfiske](https://forums.kodeco.com/u/elliotfiske)\ **Replies:** 0\ **Last updated:** [September 12, 2024, 6:17pm UTC](https://forums.kodeco.com/t/broken-link-in-chapter-25/206416 "2024-09-12T18:17:41Z")
The link should be: https://lldb.llvm.org/python\_reference/lldb-module.html#eMatchTypeRegex It’s currently https://lldb.llvm.org/python\_reference/\_lldb%27-module.html#eMatchTypeRegex (has a stray underscore and ') --- ## [Errata for Advanced Apple Debugging & Reverse Engineering 4th Edition](https://forums.kodeco.com/t/errata-for-advanced-apple-debugging-reverse-engineering-4th-edition/188990)
**Author:** [@jellodiil](https://forums.kodeco.com/u/jellodiil)\ **Replies:** 10\ **Last updated:** [June 18, 2024, 2:34pm UTC](https://forums.kodeco.com/t/errata-for-advanced-apple-debugging-reverse-engineering-4th-edition/188990 "2024-06-18T14:34:07Z")
Creating this topic to catch any typos and bugs in the 4th Edition of Advanced Apple Debugging & Reverse Engineering. --- ## [UPDATE - Chapter One Command Error Fix](https://forums.kodeco.com/t/update-chapter-one-command-error-fix/204448)
**Author:** [@boulomiel](https://forums.kodeco.com/u/boulomiel)\ **Replies:** 0\ **Last updated:** [May 19, 2024, 4:15am UTC](https://forums.kodeco.com/t/update-chapter-one-command-error-fix/204448 "2024-05-19T04:15:31Z")
Hey ! I wanted to share that this command: (lldb) breakpoint modify -c '(BOOL)\[NSStringFromClass((id)\[$arg1 class\]) containsString:@"ICMacTextView"\]' -G0 Will never trigger a breakpoint since the ICMacTextView is now I… --- ## [\`call\` vs. \`bl\` ARM assembly instruction](https://forums.kodeco.com/t/call-vs-bl-arm-assembly-instruction/204383)
**Author:** [@elliotfiske](https://forums.kodeco.com/u/elliotfiske)\ **Replies:** 1\ **Last updated:** [May 16, 2024, 6:22am UTC](https://forums.kodeco.com/t/call-vs-bl-arm-assembly-instruction/204383 "2024-05-16T06:22:32Z")
I’m confused by the paragraph in Chapter 13 under the heading “The ‘bl’ Opcode” – it seems like call and bl are used interchangeably. I haven’t been able to find any documentation about a call instruction on the ARM dev… --- ## [Chapter 1 : Scary Command not working](https://forums.kodeco.com/t/chapter-1-scary-command-not-working/201590)
**Author:** [@coffea](https://forums.kodeco.com/u/coffea)\ **Replies:** 2\ **Last updated:** [February 29, 2024, 9:20am UTC](https://forums.kodeco.com/t/chapter-1-scary-command-not-working/201590 "2024-02-29T09:20:55Z")
Hi, I tried to execute the “scary command” from chapter 1 and got the following error. (lldb) sys echo "$(dclass -t swift)" | grep -v \_ | grep "\\." | cut -d. -f1 | uniq | wc -l --- ## [Chapter 21 (4th ed.): findclass.py does not work after fix](https://forums.kodeco.com/t/chapter-21-4th-ed-findclass-py-does-not-work-after-fix/201838)
**Author:** [@hackvlix](https://forums.kodeco.com/u/hackvlix)\ **Replies:** 0\ **Last updated:** [January 25, 2024, 4:01pm UTC](https://forums.kodeco.com/t/chapter-21-4th-ed-findclass-py-does-not-work-after-fix/201838 "2024-01-25T16:01:42Z")
After fixing findclass.py by casting the return types in the Objective-C code to the proper types, it still does not list the classes but causes the error: error: Error \[IRForTarget\]: Couldn't resolve the class for an O… --- ## [Problems with re-signing the Wordpress App (Chapter 19 in 4th ed., Chapter 20 in 3rd ed.)](https://forums.kodeco.com/t/problems-with-re-signing-the-wordpress-app-chapter-19-in-4th-ed-chapter-20-in-3rd-ed/201809)
**Author:** [@hackvlix](https://forums.kodeco.com/u/hackvlix)\ **Replies:** 0\ **Last updated:** [January 24, 2024, 7:42pm UTC](https://forums.kodeco.com/t/problems-with-re-signing-the-wordpress-app-chapter-19-in-4th-ed-chapter-20-in-3rd-ed/201809 "2024-01-24T19:42:32Z")
Even when carefully following the steps to re-sign the WordPress app in this chapter, it fails with the error message resource fork, Finder information, or similar detritus not allowed The reason seems to be that when … --- ## [Code to enable SIP via MacOS VM project from WWDC](https://forums.kodeco.com/t/code-to-enable-sip-via-macos-vm-project-from-wwdc/189676)
**Author:** [@cupofjoe](https://forums.kodeco.com/u/cupofjoe)\ **Replies:** 1\ **Last updated:** [November 19, 2023, 1:48am UTC](https://forums.kodeco.com/t/code-to-enable-sip-via-macos-vm-project-from-wwdc/189676 "2023-11-19T01:48:58Z")
I’m just putting in the entire code here because I had compiler issues using what was there. Just pasting in what was in the book and ‘assuming’ how it landed was giving me a compiler error: Type ‘(any Error)?’ has no… --- ## [How to solve the problem of login failure using appuploader with the following prompt](https://forums.kodeco.com/t/how-to-solve-the-problem-of-login-failure-using-appuploader-with-the-following-prompt/192832)
**Author:** [@iosddd](https://forums.kodeco.com/u/iosddd)\ **Replies:** 0\ **Last updated:** [August 28, 2023, 8:03am UTC](https://forums.kodeco.com/t/how-to-solve-the-problem-of-login-failure-using-appuploader-with-the-following-prompt/192832 "2023-08-28T08:03:54Z")
I am planning to use the tool appuploader to submit and publish the app to the store. However, if I fail to log in using appuploader, I will be prompted with the following message. What should I do to resolve this issue --- ## [Successfully hiding the Editor Pane for Notepad - Ch1](https://forums.kodeco.com/t/successfully-hiding-the-editor-pane-for-notepad-ch1/189702)
**Author:** [@cupofjoe](https://forums.kodeco.com/u/cupofjoe)\ **Replies:** 0\ **Last updated:** [July 22, 2023, 1:23pm UTC](https://forums.kodeco.com/t/successfully-hiding-the-editor-pane-for-notepad-ch1/189702 "2023-07-22T13:23:37Z")
I wasn’t able to get this to work as detailed in the book using a MacOS VM. Cutting and pasting verbatim from the book I would get this error: po \[$rdi setHidden:!(BOOL)\[$rdi isHidden\]\]; error: expression failed to pa… --- ## [Chapter 5: Expression - \`error: cannot find '$R1' in scope\`](https://forums.kodeco.com/t/chapter-5-expression-error-cannot-find-r1-in-scope/189395)
**Author:** [@tonygo](https://forums.kodeco.com/u/tonygo)\ **Replies:** 1\ **Last updated:** [July 14, 2023, 8:22am UTC](https://forums.kodeco.com/t/chapter-5-expression-error-cannot-find-r1-in-scope/189395 "2023-07-14T08:22:49Z")
I’m trying to use the allocated variables given after p self ($R1 for instance), but after resuming the process and then pausing it again, I cannot access to $R1. (lldb) p self (Signals.MainContainerViewController) $R1 … --- ## [When will we see ARM version?](https://forums.kodeco.com/t/when-will-we-see-arm-version/181589)
**Author:** [@gngrwzrd](https://forums.kodeco.com/u/gngrwzrd)\ **Replies:** 2\ **Last updated:** [December 20, 2022, 10:08pm UTC](https://forums.kodeco.com/t/when-will-we-see-arm-version/181589 "2022-12-20T22:08:55Z")
when will we see ARM version? I’m already stuck on chapter 1 “$rdi” --- ## [Attach failed: attach failed ((os/kern) invalid argument)](https://forums.kodeco.com/t/attach-failed-attach-failed-os-kern-invalid-argument/177302)
**Author:** [@siddharth.kumar](https://forums.kodeco.com/u/siddharth.kumar)\ **Replies:** 1\ **Last updated:** [August 27, 2022, 6:04pm UTC](https://forums.kodeco.com/t/attach-failed-attach-failed-os-kern-invalid-argument/177302 "2022-08-27T18:04:03Z")
Getting this error while attaching LLDB to finder. Any suggestions? I am using M1 chip mac book pro. --- ## [Chapter 1 - Error: Use of undeclared identifier '$rdi'](https://forums.kodeco.com/t/chapter-1-error-use-of-undeclared-identifier-rdi/149393)
**Author:** [@m4m0ut](https://forums.kodeco.com/u/m4m0ut)\ **Replies:** 2\ **Last updated:** [December 8, 2021, 1:17pm UTC](https://forums.kodeco.com/t/chapter-1-error-use-of-undeclared-identifier-rdi/149393 "2021-12-08T13:17:43Z")
Hello everyone, I’m following the steps for reverse engineering Xcode. I’m able to attach lldb on it, put a breakpoint that is trigger when I click, but for an obscure reason I get “Use of undeclared identifier ‘$rdi’”… --- ## [How dtrace work in ReactiveCocoa?](https://forums.kodeco.com/t/how-dtrace-work-in-reactivecocoa/143668)
**Author:** [@sketchk](https://forums.kodeco.com/u/sketchk)\ **Replies:** 0\ **Last updated:** [July 6, 2021, 11:31am UTC](https://forums.kodeco.com/t/how-dtrace-work-in-reactivecocoa/143668 "2021-07-06T11:31:08Z")
I see some .d file in ReactiveCocoa 2.5, like RACSignalProvider.d, and the compiler will automatically generate a header file(RACSignalProvider.h) which name is equal to the .d(RACSignalProvider.d) file. As I know, .… --- ## [Error Compiling Registers](https://forums.kodeco.com/t/error-compiling-registers/141283)
**Author:** [@lunaticdreamer](https://forums.kodeco.com/u/lunaticdreamer)\ **Replies:** 1\ **Last updated:** [June 2, 2021, 2:47am UTC](https://forums.kodeco.com/t/error-compiling-registers/141283 "2021-06-02T02:47:26Z")
Hello, When trying to compile the registers utility I get the following error: Assembly Register Calling Convention/projects/starter/Registers/Registers/StackWalkthrough.s:40:11: error: invalid operand pop %rbp ^ Co… --- ## [V3 ePub missing chapters](https://forums.kodeco.com/t/v3-epub-missing-chapters/110999)
**Author:** [@warplydesigned](https://forums.kodeco.com/u/warplydesigned)\ **Replies:** 8\ **Last updated:** [April 22, 2021, 7:45pm UTC](https://forums.kodeco.com/t/v3-epub-missing-chapters/110999 "2021-04-22T19:45:41Z")
Just downloaded this now that I have time to go though it. I noticed the ePub version is missing a bunch of chapters that are in the TOC on the site as well as in the PDF version. Is this a bug or is one of the books ou… --- ## [Source Code Expired For iOS 14 Some Chapter](https://forums.kodeco.com/t/source-code-expired-for-ios-14-some-chapter/138008)
**Author:** [@elegantswift](https://forums.kodeco.com/u/elegantswift)\ **Replies:** 0\ **Last updated:** [April 18, 2021, 9:13am UTC](https://forums.kodeco.com/t/source-code-expired-for-ios-14-some-chapter/138008 "2021-04-18T09:13:38Z")
I found some sections of the source code have certain problems on iOS 14+, is there a source code repository to submit merge request to fix the related errors. --- ## [Source Code Download Page](https://forums.kodeco.com/t/source-code-download-page/27906)
**Author:** [@crispy8888](https://forums.kodeco.com/u/crispy8888)\ **Replies:** 6\ **Last updated:** [April 10, 2021, 5:26am UTC](https://forums.kodeco.com/t/source-code-download-page/27906 "2021-04-10T05:26:46Z")
Grab the source code for the book from here: https://www.raywenderlich.com/store/advanced-apple-debugging/advanced-apple-debugging-source-code --- ## [Lldb on interactive CLI programs - How to set a breakpoint where some output X is passed to stdout, waiting for input from the user](https://forums.kodeco.com/t/lldb-on-interactive-cli-programs-how-to-set-a-breakpoint-where-some-output-x-is-passed-to-stdout-waiting-for-input-from-the-user/115776)
**Author:** [@junxiang99](https://forums.kodeco.com/u/junxiang99)\ **Replies:** 5\ **Last updated:** [April 8, 2021, 6:14am UTC](https://forums.kodeco.com/t/lldb-on-interactive-cli-programs-how-to-set-a-breakpoint-where-some-output-x-is-passed-to-stdout-waiting-for-input-from-the-user/115776 "2021-04-08T06:14:49Z")
I am inspecting the bash executable with lldb. If I run on my terminal: ./bash It provides a new command prompt like so: bash-3.2$ I’d like to set a breakpoint just at the line where the code outputs bash-3.2$ to the… --- ## [Chapter 5: Symbolic breakpoint doesn't trigger](https://forums.kodeco.com/t/chapter-5-symbolic-breakpoint-doesnt-trigger/97227)
**Author:** [@sparklydust](https://forums.kodeco.com/u/sparklydust)\ **Replies:** 7\ **Last updated:** [March 25, 2021, 11:03pm UTC](https://forums.kodeco.com/t/chapter-5-symbolic-breakpoint-doesnt-trigger/97227 "2021-03-25T23:03:53Z")
Hello, When creating a symbolic breakpoint Signals.MasterContainerViewController.viewDidLoad() → () Then Build and Run the app, Xcode doesn’t trigger it. How come or what have I done wrong? It seems that I have done … --- ## [Some typos/technical errors](https://forums.kodeco.com/t/some-typos-technical-errors/133804)
**Author:** [@random\_user](https://forums.kodeco.com/u/random_user)\ **Replies:** 0\ **Last updated:** [February 27, 2021, 5:20pm UTC](https://forums.kodeco.com/t/some-typos-technical-errors/133804 "2021-02-27T17:20:28Z")
I noticed some typos/technical errors while reading the book. I didn’t find a way to contact the author directy, so I decided to post them here in the hope they will end up in the correct place. (I have the “Up to date… --- ## [Can \*.frameworks decompile](https://forums.kodeco.com/t/can-frameworks-decompile/133365)
**Author:** [@gautamkkr007](https://forums.kodeco.com/u/gautamkkr007)\ **Replies:** 1\ **Last updated:** [February 25, 2021, 10:19pm UTC](https://forums.kodeco.com/t/can-frameworks-decompile/133365 "2021-02-25T22:19:30Z")
Hi All Is it possible to decompile . frameworks file and see all source code in iOS?. Thanks, Gautam [Next page](https://forums.kodeco.com/c/books/advanced-apple-debugging/31.md?page=1)