Debug Failed in Xcode Simulator

Also experiencing this:

• macOS 15.4
• Xcode 16.3 (16E140, installed as RC2)
• iOS 16.3.1 Simulator (16.4 is affected by URLSession bugs)

Debugging ability is sporadic, plus, I get a popup dialog from Finder(?) that says "The file can’t be found." on every run of the app.

I've made sure the Xcode 16.3 is the selected Xcode version (I also have 16.2 installed) and have restarted Xcode twice. I have not restarted macOS since upgrading to 15.4.

Updating to Version 16.3 (16E140) seems to have solved the issue for me.

Xcode 16.3 on macOS 15.4 still crashes the debugger. In different situations, but it crashes in the same places. eg. can't debug SwiftUI on iOS simulator.

+1 for this. (FB17093798) We've tried all sorts of non-standard workarounds (LLDB init settings), swapping lldb-rpc-server versions. All to no avail.

Don't forget to boost the initial post here. Apple does see well bosted issues quicker.

Resolved by restarting the Mac(15.4 (24E248)), updating Xcode 16.2 to 16.3 and with new simulator on iOS 18.4 runs well.

I'm finding good success with the following:

echo "settings set plugin.process.gdb-remote.packet-timeout 300" > ~/.lldbinit

This is on Sequoia with XC 16.3 (16E140) running an iPhone 16 Pro simulator (18.4)

On my M1/64GB laptop, it is unmercifully slow, but I can debug and "work" with things w/o having the debugger crash and disconnect.

Same issue here after I updated from macOS 15.3 to 15.4 and Xcode 16.2 to 16.3

Message from debugger: The LLDB RPC server has crashed. You may need to manually terminate your process. The crash log is located in ~/Library/Logs/DiagnosticReports and has a prefix 'lldb-rpc-server'. Please file a bug and attach the most recent crash log. Couldn't find the Objective-C runtime library in loaded images.

This error never occurred on my local development machine before the upgrade!

This is particularly annoying because debugging is no longer possible in this state and breakpoints no longer work.

This is also the case for me. Everything ran great with Xcode 16.0 on Sequoia 15.2, breakpoints in the simulator and all.

I updated one of my machines to 15.4 and breakpoints no longer work, getting the message Couldn't find the Objective-C runtime library in loaded images and the debugger crashes.

Not able to update to 16.3 at the moment.

The issue for me was a Simulator that would not run on Xcode 16.3 after upgrading to Sequoia 15.4. Restart solved this.

I have the same issue, Xcode : Version 16.2 (16C5032a) Simulator : 18.3

Message from debugger: The LLDB RPC server has crashed. You may need to manually terminate your process. The crash log is located in ~/Library/Logs/DiagnosticReports and has a prefix 'lldb-rpc-server'. Please file a bug and attach the most recent crash log.

@MCStoufer1's suggestion helped, I can now successfully pause at breakpoints. However, I can't debug. Printing out anything just gives me the memory address of the variable as opposed to it's value. The second I hit a breakpoint, lldb spits out:

Couldn't find the Objective-C runtime library in loaded images

Running Xcode 16.3 and macos 15.4.

This is a massive blocker for me.

MCStoufer1's suggestion helped, I can now successfully pause at breakpoints.

At first, I also thought this solution would help. But after a short time, the problem reappeared despite the setting, even when I reinstalled Xcode 16.2.

So it doesn't seem to matter if I use Xcode 16.3 or Xcode 16.2, I always have this problem on MacOS 15.4 with both iOS 18.2 and 18.4 simulators.

I have just observed another symptom of this error: If you start an app in an iOS Simulator without active breakpoints and then add a breakpoint at runtime, the app may freeze completely.

Something seems to be completely broken with macOS 15.4 and Xcode's LLDB RPC server.

It started working after updating xcode to 16.3/ iOS 18.4. mac OS: 15.4

I had this issue after updating from macOS 15.3 to 15.3 Sequoia and fix my issue after uninstall Xcode 16.0 and every developer tool (command lines, etc)

installing again the required version (16.0 in my case) install the command tools

install Xcode 16.3 -> install developer tools

now on the version that I had the issue 16.0 the command line tools version is 16.3 (16E140) instead of the 16.0, weird but it worked like that