Issue: Test Application Based On SingleEntrySwift Not Receiving Device Arrival Delegate Messages

[benpackard]

Your Socket Mobile Developer ID

95d04909-54d4-ee11-9079-000d3a5cb302

Environment

iOS 26
CaptureSDK 2.0.31
Scanner D840

Description

I have attached an example project that demonstrates the issue. I have attempted to integrate the CaptureSDK, including the following steps:

• Added the CaptureSDK via SPM
• Added Queried URL Schemes, Supported external accessory protocols, and necessary camera/bluetooth usage descriptions to info.plist
• Registered the app on the developer portal and added the necessary keys via SKTAppInfo
• Pushed a delegate to to the CaptureHelper - I used the same CaptureSdkHandler as per the SingleEntrySwift demo project to keep things as similar as possible.

I successfully see the log messages for scanned barcodes via didReceiveDecodedData, so I know the scanner is connected to the iOS device and able to communicate. However, the device arrival/removal messages are never logged. Specifically, I am not seeing the expected messages from didNotifyArrivalForDevice and didNotifyArrivalForDevice. This is despite the fact that when I run the SingleEntrySwift demo, I do receive the expected device arrival/removal messages.

Is there some additional configuration or registration step that is not documented or that I am missing?

SocketDeviceArrivalTest.zip

Steps to Reproduce

1. Connect a scanner (I used the D840) to an iPhone (mine is running iOS 26).
2. Run the attached Xcode project.
3. Scan a barcode and confirm that the Decoded Data logs are generated in the console as expected.
4. Observe that there are no logs generated in the console for the scanner's arrival on launch, or if the scanner is turned off and back on again.
5. Run the Socket Mobile demo project SingleEntrySwift and observe that the device arrival/removal logs are generated in the console.

Expected Behavior

Prior to scanning the barcode, I would expect to see the device arrival log in the console, as I do with SingleEntrySwift.

Actual Behavior

No scanner arrival/removal logs are generated.

Additional Context

I have spent a few hours combing through my attached project and comparing it to SingleEntrySwift but have been unable to determine why mine does not register device arrival/removal.

[cyrille-socket]

Hello @benpackard,

thank you for submitting this issue.

That is very strange indeed. I have tested on iOS 26, the delegate for device arrival is not called in our CaptureHelper BUT if I test on iOS 18, it is called. Same code, same app, same CaptureSDK.

I will investigate further. In the meantime, can you try on your end with an iOS 18 device just to make sure we have the same behaviors please?

Thank you
Cyrille

[cyrille-socket]

Hello again @benpackard,

after some tests, the conclusion is that there's indeed an issue with Xcode 26.1 at least. If I run your app on Xcode 16 it works. My take is that there might have a change in Swift. I installed then Xcode 26.1.1 and same result. The Xcode 26.2 is in RC at the moment. Waiting for the final to test again.

Can you downgrade to Xcode 16 in the meantime?

In addition to that, it's the delegate that is not called from our CaptureHelper but the device is opened and functional on the CaptureSDK point of view and you can scan. So the only thing that you're missing is the fact that you cannot update your UI with the scanners list at the moment.

[benpackard]

Many thanks for the fast response as always. I will check today. One thing though - when you run the SingleEntryTest demo from https://github.com/SocketMobile/capturesingleentryswift-ios with the exact same version of Xcode 26 and CaptureSDK what do you find? I was able to see the device arrival and removal notifications in this setup, which is what convinced me it must be something in the way my example was configured rather than the SDK or the environment. Ben

…

On Dec 9, 2025 at 8:17 AM -0500, Cyrille ***@***.***>, wrote: cyrille-socket left a comment (SocketMobile/swift-package-capturesdk#35) Hello again @benpackard, after some tests, the conclusion is that there's indeed an issue with Xcode 26.1 at least. If I run your app on Xcode 16 it works. My take is that there might have a change in Swift. I installed then Xcode 26.1.1 and same result. The Xcode 26.2 is in RC at the moment. Waiting for the final to test again. Can you downgrade to Xcode 16 in the meantime? — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you were mentioned.Message ID: ***@***.***>

[cyrille-socket]

Hello @benpackard,

indeed that is strange because if I run my SingleEntry app it works fine with Xcode 26 and iOS26 or iOS18. Your code is the same though.

But the "test" of the delegate object in our CaptureHelper that sends the device arrival is failing which makes no sense. Keep you posted after Xcode 26.2 release which is imminent hopefully.

[benpackard]

Just confirming that yes, I was also able to receive the notifications when building from Xcode 16.4 even when still deploying to iOS 26.

I am slightly skeptical that this will be resolved by the next Xcode update, only because of that strange case where your SingleEntry app is already working fine. But hopefully that will resolve it, and it is at least worth waiting to find out.

As you say, the scanning delegate fires just fine which is most important. But connectivity monitoring is very helpful for onsite setup and remote assistance since our apps display and report when no scanner is connected. I think if all else fails I might have to start a new project from the SingleEntry demo, strip out everything from it, and slowly start adding back my own code to build our app back up. It is baffling though why one would work and not the other!

[cyrille-socket]

Ok that's a start that we at least have the same behavior. Let's wait for Xcode 26.2 and see if the issue is still there and then we can think about a plan.

Another test would be to lower the Swift version in the Build settings of your project. I did not test that yet but could be a workaround if Swift version is incriminated, which is my take at the moment.

[benpackard]

I had the same thought. Unfortunately not. On Xcode 16, both Swift 5 and Swift 6 send the notifications. On Xcode 26, no notifications are sent for either language version.

However... along with Swift 6, Xcode also includes compiler flags in the build settings for Approachable Concurrency and Default Actor Isolation.

1. When creating a new project in Xcode 26, these are set by default as follows:

Swift Language version: 5
Approachable Concurrency: YES
Default Actor Isolation: MainActor
Strict Concurrency Checking: Minimal

Under these conditions, I do not see the notifications.

2. If I change them to:

Swift Language version: 5
Approachable Concurrency: NO
Default Actor Isolation: nonisoloated
Strict Concurrency Checking: Minimal

I do get some notifications but very quickly I get Capture SDK Error -27 and no more notifications.

3. Once I switch to Swift 6 on a new project, the flag for Strict Concurrency Checking updates automatically (it uses SWIFT_STRICT_CONCURRENCY_DEFAULT, which is different for Swift 6 vs Swift 5), so we now have:

Swift Language version: 6
Approachable Concurrency: YES
Default Actor Isolation: MainActor
Strict Concurrency Checking: Complete

And again, no notifications.

4. But if I set it as follows:

Swift Language version: 6
Approachable Concurrency: NO
Default Actor Isolation: Nonisoloated
Strict Concurrency Checking: Complete

We are back to initially getting notifications, but then a Capture SDK Error -27 and no notifications.

At this point I am just sticking my screwdriver in the engine and waggling it around without much idea of the reasoning, but including it in case it helps debug.

For me, the goal is to be able to use the SDK on Xcode 26 with default Swift 6 flags (example 3), or if not then at least the default settings for a new project (example 1)

[cyrille-socket]

Hello @benpackard

thank you for this deep analysis. I'll try to find the right combination and see if the -27 error can be worked around, or the whole issue of course.

Xcdode 26.2 has been released. I'll test with it too.

Keep you posted.

[cyrille-socket]

Hello @benpackard and Happy new year!

I tried with Xcode 26.2 and the issue is still there. I'll try also with the combinations that you tried on your end and I'll keep you posted.

[benpackard]

Happy new year @cyrille-socket. Sounds good, for now I am building with Xcode 16 without issue.

[thom-ek]

Will this be ever fixed? Xcode 26 is for a while here and bug still exists.

[cyrille-socket]

Hello @benpackard @thom-ek,

we still working on this one. It should be fixed for next release. It is really hard to catch and fix with the architecture that we have in our CaptureSDK.

[cyrille-socket]

Hello @benpackard and @thom-ek

we have fixed this issue in the new release here: https://github.com/SocketMobile/swift-package-capturesdk/releases/tag/2.0.73

Please let me know if that works for you.

Best
Cyrille

[benpackard]

Thanks @cyrille-socket I will verify at the earliest opportunity. Any comment on what caused this out of interest?

[cyrille-socket]

Based on your experiments and mines, seems like the dispatch queue blocks are triggered differently depending on Swift Language version, Approachable Concurrency, Default Actor Isolation and Strict Concurrency Checking. Now it works in every condition.