AWSCognitoAuthPlugin fails to compile against the visionOS 27 SDK: excludedCredentials (visionOS 1.1) used under @available(visionOS 1.0); no .visionOS platform in Package.swift #4237

Describe the bug

AWSCognitoAuthPlugin fails to compile for visionOS when built with the visionOS 27 SDK (Xcode 27).

PlatformWebAuthnCredentials.swift assigns ASAuthorizationPlatformPublicKeyCredentialRegistrationRequest.excludedCredentials — which the visionOS SDK annotates @available(visionOS 1.1, *) — inside an extension annotated @available(iOS 17.4, macOS 13.5, visionOS 1.0, *). Because amplify-swift's Package.swift declares no visionOS platform, SwiftPM derives a visionOS 1.0 deployment floor for the package, so the 1.1 API usage is a hard error:

…/AWSCognitoAuthPlugin/Actions/SignIn/WebAuthn/PlatformWebAuthnCredentials.swift:116:28: \
error: 'excludedCredentials' is only available in visionOS 1.1 or newer

This blocks every visionOS app that depends on AWSCognitoAuthPlugin — including apps that never use WebAuthn/passkeys — when building against the visionOS 27 SDK.

Steps to reproduce

1. A visionOS app target depending on amplify-swift AWSCognitoAuthPlugin.
2. Build for the visionOS 27 simulator with Xcode 27 (visionOS 27.0 SDK).
3. Compilation of the AWSCognitoAuthPlugin target fails in PlatformWebAuthnCredentials.swift at the excludedCredentials assignment.

Root cause

• Package.swift → platforms: [.iOS(.v13), .macOS(.v12), .tvOS(.v13), .watchOS(.v9)] — no .visionOS, so the visionOS deployment floor derives to 1.0.
• extension PlatformWebAuthnCredentials: CredentialRegistrantProtocol is @available(iOS 17.4, macOS 13.5, visionOS 1.0, *).
• Inside create(with:):

  platformKeyRequest.excludedCredentials = options.excludeCredentials.compactMap { credential in
      return .init(credentialID: credential.id)
  }

  In the visionOS 27 SDK, excludedCredentials is @available(visionOS 1.1, *). With a visionOS 1.0 floor and no if #available guard, this is an error. (Earlier visionOS SDKs evidently annotated this differently / did not enforce it, so it surfaces specifically with the visionOS 27 SDK.)

Suggested fix

Any of:

1. Guard the usage: wrap the excludedCredentials assignment in if #available(visionOS 1.1, iOS 17.4, *), or
2. Raise the availability of the enclosing create(with:) / extension to visionOS 1.1, and/or
3. Declare a visionOS platform in Package.swift so consumers and the package itself get a correct (≥ 1.1) floor.

Consumer workaround (until fixed)

Force the package's visionOS deployment target up at build time — command-line build settings apply to SwiftPM package targets:

xcodebuild … XROS_DEPLOYMENT_TARGET=27.0 build

Environment

• Amplify version: 2.51.1 (also present in the latest 2.58.3 — the Package.swift platforms and the unguarded usage are unchanged)
• Dependency manager: Swift Package Manager
• Xcode: 27.0 (27A5194q), Swift 6.4
• SDK / target: visionOS 27.0 (simulator and device), arm64-apple-xros27.0