iOS builds broken since LineSDK 5.17.0: "The package product 'LineSDK' requires minimum platform version 15.0, but this target supports 13.0" (SwiftPM)

Summary

Since line-sdk-ios-swift 5.17.0 was released (2026-07-23T10:28Z, via line/line-sdk-ios-swift#257 raising the minimum deployment target to iOS 15.0), every Flutter iOS build using Swift Package Manager fails at archive time for apps depending on flutter_line_sdk 2.7.2:

error: The package product 'LineSDK' requires minimum platform version 15.0 for the iOS platform,
but this target supports 13.0 (in target 'flutter_line_sdk' from project 'flutter_line_sdk')

Root cause

ios/flutter_line_sdk/Package.swift in 2.7.2 declares:

platforms: [
    .iOS("13.0"),
],
dependencies: [
    .package(url: "https://github.com/line/line-sdk-ios-swift.git", from: "5.13.0")
]

• The dependency has no upper bound, so a fresh SPM resolution now picks 5.17.0, whose manifest declares platforms: [.iOS("15.0")].
• The plugin's own platforms: [.iOS("13.0")] then conflicts, and Xcode's Target Integrity check fails.

Because most Flutter projects do not commit Package.resolved for the workspace, CI systems re-resolve on every build — so builds that succeeded yesterday fail today with zero code changes.

Environment

• flutter_line_sdk: 2.7.2 (latest)
• Flutter 3.44.2 (SPM enabled), Xcode 26.6
• App's own iOS deployment target: 15.6 (i.e. the app itself is fine with iOS 15 — the conflict is purely the plugin manifest)

Verified findings

• Same commit: built successfully at 2026-07-23T07:29Z (resolved LineSDK 5.16.1), failed at 12:32Z (resolved 5.17.0).
• Raising all IPHONEOS_DEPLOYMENT_TARGET values in the app's Xcode project to 15.6 does not help — the 13.0 in the error is this plugin's own manifest platform, as the (in target 'flutter_line_sdk') suffix shows.
• Pinning line-sdk-ios-swift back to 5.16.1 in Package.resolved builds fine.

The CocoaPods path may also be affected for apps with a deployment target below 15.0, since the podspec declares s.dependency 'LineSDKSwift', '~> 5.16', which permits 5.17.0 (not verified — our app uses SPM).

Workaround (for other users hitting this)

Commit ios/Runner.xcworkspace/xcshareddata/swiftpm/Package.resolved with LineSDK pinned to 5.16.1:

{
  "identity" : "line-sdk-ios-swift",
  "kind" : "remoteSourceControl",
  "location" : "https://github.com/line/line-sdk-ios-swift.git",
  "state" : {
    "revision" : "642f38e02c1bc777befbc4540650d77d4c46d858",
    "version" : "5.16.1"
  }
}

Suggested fix

Release a plugin update that either:

1. raises the plugin manifest to platforms: [.iOS("15.0")] (and podspec s.ios.deployment_target) to align with LineSDK 5.17.0, or
2. constrains the dependency to "5.13.0"..<"5.17.0" as a hotfix for projects still targeting iOS 13/14, with option 1 as a follow-up.

Thanks for maintaining the SDK!

Start with ios/flutter_line_sdk/Package.swift and the plugin podspec, then reproduce a fresh Swift Package Manager resolution using LineSDK 5.17.0. Align the dependency and deployment-target metadata according to the chosen fix, and verify that a fresh Flutter iOS archive succeeds without the platform-version conflict.