PlatformNotSupported MacOS

Describe the bug We’ve decided to update MacOS + Xamarin + XCode to the latest stable versions. That made us update your library from 2.2.5 to 2.5.1 (latest currently). The cli started to throw exception System.PlatformNotSupportedException: Operation is not supported on this platform.

To Reproduce Steps to reproduce the behavior:

var cli = new CommandLineApplication();
cli.Execute(emptyArgs);

Expected behavior Work as usual.

Additional context Full stacktrace:

System.PlatformNotSupportedException: Operation is not supported on this platform.
  at System.Console.remove_CancelKeyPress (System.ConsoleCancelEventHandler value) [0x00000] in /Library/Frameworks/Xamarin.Mac.framework/Versions/Current/src/Xamarin.Mac/mcs/class/corlib/System/Console.cs:947 
  at McMaster.Extensions.CommandLineUtils.PhysicalConsole.remove_CancelKeyPress (System.ConsoleCancelEventHandler value) [0x00000] in <7f833d3ed5424320a314ef2658925b83>:0 
  at McMaster.Extensions.CommandLineUtils.CommandLineApplication.ExecuteAsync (System.String[] args, System.Threading.CancellationToken cancellationToken) [0x00137] in <7f833d3ed5424320a314ef2658925b83>:0 
  at McMaster.Extensions.CommandLineUtils.CommandLineApplication.Execute (System.String[] args) [0x00016] in <7f833d3ed5424320a314ef2658925b83>:0 
  at Launcher.MainClass.Main (System.String[] args) [0x00144] in /Users/gameforest/Desktop/Citrus/Orange/Launcher/Main.cs:388

Full info about system:

=== Visual Studio Community 2019 for Mac ===

Version 8.4.5 (build 19)
Installation UUID: 877191a5-d7c4-4943-99dc-315c0d7d6560
  GTK+ 2.24.23 (Raleigh theme)
  Xamarin.Mac 5.16.1.25 (issue-7441-d16-3-vsmac / 881172e73)

  Package version: 606000155

=== Mono Framework MDK ===

Runtime:
  Mono 6.6.0.155 (2019-08/296a9afdb24) (64-bit)
  Package version: 606000155

=== Roslyn (Language Service) ===

3.4.0-beta4-19562-05+ff930dec4565e2bc424ad3bf3e22ecb20542c87d

=== NuGet ===

Version: 5.3.0.6192

=== .NET Core SDK ===

SDK: /usr/local/share/dotnet/sdk/3.1.101/Sdks
SDK Versions:
  3.1.101
  2.0.0
MSBuild SDKs: /Library/Frameworks/Mono.framework/Versions/6.6.0/lib/mono/msbuild/Current/bin/Sdks

=== .NET Core Runtime ===

Runtime: /usr/local/share/dotnet/dotnet
Runtime Versions:
  3.1.1
  2.1.15
  2.0.0

=== Xamarin.Profiler ===

Version: 1.6.13.11
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

=== Updater ===

Version: 11

=== Xamarin.Android ===

Version: 10.1.3.7 (Visual Studio Community)
Commit: xamarin-android/d16-4/d66aed0
Android SDK: /Users/gameforest/Library/Developer/Xamarin/android-sdk-macosx
  Supported Android versions:
    4.4    (API level 19)
    4.4.87 (API level 20)
    5.0    (API level 21)
    5.1    (API level 22)
    6.0    (API level 23)
    7.0    (API level 24)
    7.1    (API level 25)
    8.0    (API level 26)
    8.1    (API level 27)

SDK Tools Version: 26.1.1
SDK Platform Tools Version: 29.0.4
SDK Build Tools Version: 28.0.3

Build Information: 
Mono: fd9f379
Java.Interop: xamarin/java.interop/d16-4@c4e569f
ProGuard: xamarin/proguard/master@905836d
SQLite: xamarin/sqlite/3.28.0@46204c4
Xamarin.Android Tools: xamarin/xamarin-android-tools/master@9f4ed4b

=== Microsoft Mobile OpenJDK ===

Java SDK: /Users/gameforest/Library/Developer/Xamarin/jdk/microsoft_dist_openjdk_1.8.0.25
1.8.0-25
Android Designer EPL code available here:
https://github.com/xamarin/AndroidDesigner.EPL

=== Android SDK Manager ===

Version: 16.4.0.10
Hash: 2c49a7d
Branch: remotes/origin/d16-4
Build date: 2020-01-30 10:22:44 UTC

=== Android Device Manager ===

Version: 16.4.0.30
Hash: f9172e2
Branch: remotes/origin/d16-4
Build date: 2020-01-30 10:23:04 UTC

=== Xamarin Designer ===

Version: 16.4.0.479
Hash: 074544417
Branch: remotes/origin/d16-4
Build date: 2020-01-22 22:50:22 UTC

=== Apple Developer Tools ===

Xcode 11.3.1 (15715)
Build 11C504

=== Xamarin.Mac ===

Version: 6.10.0.17 (Visual Studio Community)
Hash: 5f802ef53
Branch: xcode11.3
Build date: 2020-01-07 11:53:06-0500

=== Xamarin.iOS ===

Version: 13.10.0.17 (Visual Studio Community)
Hash: 5f802ef53
Branch: xcode11.3
Build date: 2020-01-07 11:53:06-0500

=== Xamarin Inspector ===

Version: 1.4.3
Hash: db27525
Branch: 1.4-release
Build date: Mon, 09 Jul 2018 21:20:18 GMT
Client compatibility: 1

=== Build Information ===

Release ID: 804050019
Git revision: 5b9e12b8142016693a4b0f0bdac84ffac1d84c28
Build date: 2020-02-07 12:51:25+00
Build branch: release-8.4
Xamarin extensions: 5b9e12b8142016693a4b0f0bdac84ffac1d84c28

=== Operating System ===

Mac OS X 10.15.3
Darwin 19.3.0 Darwin Kernel Version 19.3.0
    Thu Jan  9 20:58:23 PST 2020
    root:xnu-6153.81.5~1/RELEASE_X86_64 x86_64

[natemcmaster]

Are you able to keep using 2.2.5 until we can fix this? Seems like a simple fix would be to suppress this exception around this line: https://github.com/natemcmaster/CommandLineUtils/blob/fa06ab9b41b390fc7d1e6e0a9783a1b3882f1bb9/src/CommandLineUtils/CommandLineApplication.cs#L917-L920

Also (rhetorical question), why in the world does Xamarin allow adding an event handler to ConsoleKeyPress, but not removing that same handler?

[helviett]

As a workaround for the Xamarin issue, I suggest you implement IConsole (you could copy from the source for PhysicalConsole), but make the CancelKeyPress handler no-op.

the version of library doesn’t matter, cause we experience the same issue on 2.2.5 on Mojave.

You are getting the same stack trace and error in 2.2.5? Are you 100% sure? There is no usage of CancelKeyPress in v2.2.5. Please check if this is another error.

Perhaps I was mistaken. Can’t reproduce it now. Thank you for your workaround 😃