I upgraded Flutter to latest. Following is the doctor output
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v0.8.2, on Mac OS X 10.14 18A326h, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK 28.0.1)
[✓] iOS toolchain - develop for iOS devices (Xcode 10.0)
[✓] Android Studio (version 3.1)
[✓] VS Code (version 1.27.1)
When I run the app with target to iOS simulator, I get this
Launching lib/main.dart on iPhone XS Max in debug mode...
Starting Xcode build...
Xcode build done.
Failed to build iOS app
Error output from Xcode build:
↳
** BUILD FAILED **
Xcode's output:
↳
error: Multiple commands produce '/Users/kalehv/dev/todo/todo-flutter/build/ios/Debug-iphonesimulator/Runner.app/Frameworks/Flutter.framework':
1) Target 'Runner' has copy command from '/Users/kalehv/dev/todo/todo-flutter/ios/Flutter/Flutter.framework' to '/Users/kalehv/dev/todo/todo-flutter/build/ios/Debug-iphonesimulator/Runner.app/Frameworks/Flutter.framework'
2) That command depends on command in Target 'Runner': script phase “[CP] Embed Pods Frameworks”
warning: The use of Swift 3 @objc inference in Swift 4 mode is deprecated. Please address deprecated @objc inference warnings, test your code with “Use of deprecated Swift 3 @objc inference” logging enabled, and then disable inference by changing the "Swift 3 @objc Inference" build setting to "Default" for the "Runner" target. (in target 'Runner')
warning: ignoring duplicated output file: '/Users/kalehv/dev/todo/todo-flutter/build/ios/Debug-iphonesimulator/Runner.app/Frameworks/Flutter.framework' (in target 'Runner')
note: Using new build systemnote: Planning buildnote: Constructing build description
Could not build the application for the simulator.
Error launching application on iPhone XS Max.
I think this would help at least it worked for me url.
Open your Xcode and there is File upper-left next to Apple icon, then open Workspace Settings and change the build system to Legacy Build System.