Swift 6 Concurrency issue

[hammas1993]

After switching to swift 6 app crashes on msalApplication.acquireTokenSilent(with: parameters)....!

[kaisong1990]

Hi @hammas1993 can you please share some sample code and crash logs? Thanks

[hammas1993]

msalApplication.acquireTokenSilent(with: parameters)
{ (result, error) in
}
using this func in swift 6 creates this crash and if i remove the func the error doesn't occur

[djohnson-obdev]

I'm having the same issue. Is there a workaround? If I use the async version of that method, the compiler is complaining that MSALResult doesn't conform to Sendable.

[kaisong1990]

Thanks for reporting, the issue was fixed in dev branch and will be shipped in our next release (ETA end of Feb)

[techios056]

I'm having the similar crash while configuring self.application = try MSALPublicClientApplication(configuration: pcaConfig).

Is there a workaround? As its not using either @sendable or @escaping to handle concurrency. I have tried using async call and updated to latest MSAL version (1.9.0) but nothing is working. Adding the screenshot for the crash below: -

Thanks in advance!

[stack]

I am seeing similar crashes when enabling Swift 6 language mode and Approachable Concurrency.

I've verified that MSALPublicClientApplication is being created on the main thread, which then dispatches internally and crashes, as shown in the issue above.

There is no crash with Swift 5 language mode and Approachable Concurrency.

[stack]

I am still seeing this with version 2.8.2

[kaisong1990]

Hi @stack and @techios056, could you please try either of the options and let us know if the crash persists?

Wrap the call to force it onto the main actor:

  func setup() async throws {
      self.application = try await MainActor.run {
          try MSALPublicClientApplication(configuration: pcaConfig)
      }
  }

Or annotate the surrounding type/function with @MainActor:

  @MainActor
  func setup() throws {
      self.application = try MSALPublicClientApplication(configuration: pcaConfig)
  }

[stack]

@kaisong1990 I'm still seeing the same issue. To be clear, this is with the "Approachable Concurrency" setting set to Yes. (Target -> Build Settings -> Approachable Concurrency). This effectively makes everything @MainActor by default in the app.

I double checked by also annotating my setup function with @MainActor, but that doesn't change anything. The crash is happening in a dispatch thread, not the main thread. I did verify that the MSALPublicClientApplication instantiation is started on the main thread.

[stack]

This still occurs with 2.10.0. Xcode 26.4.

[stack]

Here is a sample app that crashes in the same way.

This is a new project created with Xcode 26.4. Swift language mode is set to Swift 6.

Edit the ContentView.swift file with proper values and run to crash.

MSALCrash.zip