How can I start debugging a `dyld` error

Using Swift
1

How can I begin to debug why a library is not being loaded at compile time?

I feel like I’m a bit outside of my league here because I’ve never run into this type of error before. I’m getting a crash at run time when trying to run my project on the simulator (iOS).

Screenshot 2025-10-18 at 4.18.16 PM
Screenshot 2025-10-18 at 4.18.16 PM1396×596 59.9 KB

I started seeing this after I added a package that I created. To troubleshoot I created a new project and imported the same newly created package and it worked with no problems. So I know the problem is not with the package itself. I have since deleted DerivedData multiple times to no avail.

I see this output in the console after the crash

Library not loaded: /usr/lib/swift/libLiveExecutionResultsLogger.dylib

Referenced from: <8832D1F6-D3B4-350E-AE16-2FC1D54612E9> /Users/…/Library/Developer/CoreSimulator/Devices/3C85B758-3216-40B4-B488-AA05BABEC9F3/data/Containers/Bundle/Application/CE6A73EB-3572-4285-9074-8B54FC2D3132/

Reason: tried: '/Users/…/Library/Developer/Xcode/DerivedData/…-gnmdkprcrvllgsfpsajpeqkvsbob/Build/Products/Release-iphonesimulator/libLiveExecutionResultsLogger.dylib' (no such file),

I don’t know where to begin to debug this so I don’t which output to provide to request help. Any help is appreciated, thanks!

2

For what it’s worth, libLiveExecutionResultsLogger is Playgrounds related. So to work around this issue you can comment out all import Playgrounds.

I'm getting this in both Swift packages and Xcode projects, even after entirely reinstalling both Swift and Xcode. I'm not aware of a proper solution. I've filed a feedback (FB18028542) early during the betas and got some follow up questions, but unfortunately work on it seems to have been interrupted at some point.

2 Likes
3

So grateful for this insight. I spent an hour or so debugging this.

4

Thanks for this post. Got hit by this, too. Was just trying to add a package to my Vapor project using Xcode 26.1.1. The package has import Playgrounds in two files and can run its unit tests without the crash. I can also use it in an iOS app with no issues. The Vapor app immediately crashes.

Edit: seems to only happen if the Vapor project depends on … fluent-postgres-driver :thinking: