Intermittent app crash SocketException No such host is known

[garie]

Bug

Plugin Version: 1.1.2 Platform: iOS 13.6.1
Device/Hardware: iPad 6th Gen, WiFi

This was reported by Apple and my app was rejected because of it. I wasn't able to reproduce the issue locally so I'm not sure if it is dependent upon a server being down or anything like that. I looked at your code and it's got a catch (Exception) so I don't understand why this caused a crash. I'm suspicious of the RedirectHandler in there - maybe itunes.apple.com returned a 3xx response? In any case, I have no idea what the issue is or how to fix it.

Stack trace SIGABRT: SocketException No such host is known

ConnectHelper.ConnectAsync (System.String host, System.Int32 port, System.Threading.CancellationToken cancellationToken)
HttpConnectionPool.CreateConnectionAsync (System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
HttpConnectionPool.WaitForCreatedConnectionAsync (System.Threading.Tasks.ValueTask`1[TResult] creationTask)
HttpConnectionPool.SendWithRetryAsync (System.Net.Http.HttpRequestMessage request, System.Boolean doRequestAuth, System.Threading.CancellationToken cancellationToken)
RedirectHandler.SendAsync (System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
HttpClient.FinishSendAsyncBuffered (System.Threading.Tasks.Task`1[TResult] sendTask, System.Net.Http.HttpRequestMessage request, System.Threading.CancellationTokenSource cts, System.Boolean disposeCts)
LatestVersionImplementation.GetLatestVersionNumber (System.String appName)
LatestVersionImplementation.GetLatestVersionNumber ()
LatestVersionImplementation.IsUsingLatestVersion ()

[garie]

Looking through some App Center diagnostics from a few days ago, I actually see a similar (not identical) crash on Android 10 on a Pixel. I didn't investigate the crash at the time it happened but this was a real device which was connected to my home WiFi which didn't have any hiccups as far as I'm aware.

System.IO.IOException: Remote prematurely closed connection.
AsyncProtocolRequest.ProcessOperation (System.Threading.CancellationToken cancellationToken) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/System/Mono.Net.Security/AsyncProtocolRequest.cs:211
AsyncProtocolRequest.StartOperation (System.Threading.CancellationToken cancellationToken) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/System/Mono.Net.Security/AsyncProtocolRequest.cs:187
MobileAuthenticatedStream.ProcessAuthentication (System.Boolean runSynchronously, Mono.Net.Security.MonoSslAuthenticationOptions options, System.Threading.CancellationToken cancellationToken) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/System/Mono.Net.Security/MobileAuthenticatedStream.cs:310
ConnectHelper.EstablishSslConnectionAsyncCore (System.IO.Stream stream, System.Net.Security.SslClientAuthenticationOptions sslOptions, System.Threading.CancellationToken cancellationToken) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/ConnectHelper.cs:165
ConnectHelper.EstablishSslConnectionAsyncCore (System.IO.Stream stream, System.Net.Security.SslClientAuthenticationOptions sslOptions, System.Threading.CancellationToken cancellationToken) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/ConnectHelper.cs:176
ValueTask`1[TResult].get_Result () /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/Common/src/CoreLib/System/Threading/Tasks/ValueTask.cs:813
HttpConnectionPool.CreateConnectionAsync (System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs:408
ValueTask`1[TResult].get_Result () /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/Common/src/CoreLib/System/Threading/Tasks/ValueTask.cs:813
HttpConnectionPool.WaitForCreatedConnectionAsync (System.Threading.Tasks.ValueTask`1[TResult] creationTask) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs:543
ValueTask`1[TResult].get_Result () /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/Common/src/CoreLib/System/Threading/Tasks/ValueTask.cs:813
HttpConnectionPool.SendWithRetryAsync (System.Net.Http.HttpRequestMessage request, System.Boolean doRequestAuth, System.Threading.CancellationToken cancellationToken) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs:284
RedirectHandler.SendAsync (System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/RedirectHandler.cs:32
HttpClient.FinishSendAsyncBuffered (System.Threading.Tasks.Task`1[TResult] sendTask, System.Net.Http.HttpRequestMessage request, System.Threading.CancellationTokenSource cts, System.Boolean disposeCts) /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Net.Http/src/System/Net/Http/HttpClient.cs:506
LatestVersionImplementation.GetLatestVersionNumber (System.String appName) C:\projects\latestversionplugin\src\Plugin.LatestVersion.Android\LatestVersionImplementation.cs:69
LatestVersionImplementation.GetLatestVersionNumber () C:\projects\latestversionplugin\src\Plugin.LatestVersion.Android\LatestVersionImplementation.cs:49
LatestVersionImplementation.IsUsingLatestVersion () C:\projects\latestversionplugin\src\Plugin.LatestVersion.Android\LatestVersionImplementation.cs:36

[garie]

I wrapped the call to IsUsingLatestVersion in a try-catch and added error tracking in the catch so I'll see if this happens again and report back.