VS 4 Mac beta - Socket error on UITest tests

[owenniblock]

Steps to Reproduce

1. Download code sample: https://github.com/King-of-Spades/AppCenter-Test-Samples/tree/master/Xamarin.UITest/UITestDemo
2. Switch VS 4 Mac to beta channel
3. Open Android emulator & select in VS 4 Mac
4. Run Android tests

Expected Behavior

Tests run successfully (they run correctly on VS 4 Mac stable).

Actual Behavior

Tests fail to run either with error:

SetUp : System.Net.Http.HttpRequestException : An error occurred while sending the request
  ----> System.Net.WebException : Unable to read data from the transport connection: Connection reset by peer.
  ----> System.IO.IOException : Unable to read data from the transport connection: Connection reset by peer.
  ----> System.Net.Sockets.SocketException : Connection reset by peer

or error:

SetUp : System.Net.Http.HttpRequestException : An error occurred while sending the request
  ----> System.IO.IOException : Unable to write data to the transport connection: The socket is not connected.
  ----> System.Net.Sockets.SocketException : The socket is not connected

Version Information

=== Visual Studio Community 2017 for Mac (Preview) ===

Version 7.6 Preview (7.6 build 947)
Installation UUID: 088a769e-be74-4fd9-b64b-065d830c7305
Runtime:
Mono 5.12.0.260 (2018-02/58637d0ee7c) (64-bit)
GTK+ 2.24.23 (Raleigh theme)
Xamarin.Mac 4.4.0.36 (master / 0c7c49a6)

Package version: 512000260

=== NuGet ===

Version: 4.3.1.4445

=== .NET Core ===

Runtime: /usr/local/share/dotnet/dotnet
Runtime Versions:
2.0.5
2.0.0
SDK: /usr/local/share/dotnet/sdk/2.1.4/Sdks
SDK Versions:
2.1.4
2.0.2
2.0.0
MSBuild SDKs: /Library/Frameworks/Mono.framework/Versions/5.12.0/lib/mono/msbuild/15.0/bin/Sdks

=== Xamarin.Profiler ===

Version: 1.6.3
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

=== Apple Developer Tools ===

Xcode 9.3 (14154)
Build 9E145

=== Xamarin.Mac ===

Version: 4.5.0.331 (Visual Studio Community)
Hash: 238eb94c
Branch: master
Build date: 2018-05-25 07:47:00-0400

=== Xamarin.iOS ===

Version: 11.11.0.331 (Visual Studio Community)
Hash: 238eb94c
Branch: master
Build date: 2018-05-25 07:47:00-0400

=== Xamarin.Android ===

Version: 8.3.99.12 (Visual Studio Community)
Android SDK: /Users/owenniblock/Library/Developer/Xamarin/android-sdk-macosx
Supported Android versions:
6.0 (API level 23)
7.0 (API level 24)
7.1 (API level 25)
8.0 (API level 26)

SDK Tools Version: 25.2.5
SDK Platform Tools Version: 27.0.1
SDK Build Tools Version: 25.0.3

Java SDK: /usr
java version "1.8.0_141"
Java(TM) SE Runtime Environment (build 1.8.0_141-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.141-b15, mixed mode)

Android Designer EPL code available here:
https://github.com/xamarin/AndroidDesigner.EPL

=== Xamarin Inspector ===

Version: 1.4.0
Hash: b3f92f9
Branch: master
Build date: Fri, 19 Jan 2018 22:00:34 GMT
Client compatibility: 1

=== Build Information ===

Release ID: 706000947
Git revision: f7b338b596748ffa52b2f86a292bb52a1ce2a4fd
Build date: 2018-05-25 12:47:39-04
Xamarin extensions: 179dd16370b3fd3f3e71ef70ba136fea5e66c60c
Build lane: monodevelop-lion-master

=== Operating System ===

Mac OS X 10.13.5
Darwin 17.6.0 Darwin Kernel Version 17.6.0
Tue May 8 15:22:16 PDT 2018
root:xnu-4570.61.1~1/RELEASE_X86_64 x86_64

=== Enabled user installed extensions ===

Internet of Things (IoT) development (Preview) 7.5

Log File

--------- NOTE: Had to truncate log as it was huge - let me know if you want an upload of the whole thing.
06-13 19:07:56.090 5277 5277 I InstrumentationBackend: Added:'DumpHtml', with key:'dump_html'
06-13 19:07:56.090 5277 5277 I InstrumentationBackend: Added:'EnterTextByCssSelector', with key:'enter_text_by_selector'
06-13 19:07:56.090 5277 5277 I InstrumentationBackend: Added:'GetLoadProgress', with key:'get_load_progress'
06-13 19:07:56.090 5277 5277 I InstrumentationBackend: Added:'GetUrl', with key:'get_url'
06-13 19:07:56.090 5277 5277 I InstrumentationBackend: Added:'ScrollTo', with key:'scroll_to'
06-13 19:07:56.090 5277 5277 I InstrumentationBackend: Added:'SetPropertyByCssSelector', with key:'set_property_by_css_selector'
06-13 19:07:56.090 5277 5277 I calabash: Instantiating http server at 54604
06-13 19:07:56.091 5277 5277 I System.out: HTTP Daemon listening on: 54604
06-13 19:07:56.837 2233 2727 D EGL_emulation: eglMakeCurrent: 0xae594c00: ver 2 0 (tinfo 0xae5926f0)
06-13 19:08:00.063 1262 1321 D hwcomposer: hw_composer sent 599 syncs in 60s
06-13 19:09:00.055 1262 1321 D hwcomposer: hw_composer sent 12 syncs in 60s
06-13 19:10:00.038 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:11:00.065 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:11:34.233 1948 2100 I AccountManagerService: getTypesVisibleToCaller: isPermitted? true
06-13 19:11:34.316 5303 5303 W dex2oat : Unexpected CPU variant for X86 using defaults: x86
06-13 19:11:34.316 5303 5303 W dex2oat : Mismatch between dex2oat instruction set features (ISA: X86 Feature string: smp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2) and those of dex2oat executable (ISA: X86 Feature string: smp,ssse3,-sse4.1,-sse4.2,-avx,-avx2) for the command line:
06-13 19:11:34.316 5303 5303 W dex2oat : /system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=x86 --instruction-set-features=smp,ssse3,-sse4.1,-sse4.2,-avx,-avx2 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=x86 --instruction-set-features=default --dex-file=/data/user/0/com.google.android.gms/app_fb/f.apk --oat-file=/data/user/0/com.google.android.gms/app_fb/f.dex
06-13 19:11:34.316 5303 5303 I dex2oat : /system/bin/dex2oat --dex-file=/data/user/0/com.google.android.gms/app_fb/f.apk --oat-file=/data/user/0/com.google.android.gms/app_fb/f.dex
06-13 19:11:34.340 5303 5303 I dex2oat : dex2oat took 24.014ms (threads: 4) arena alloc=121KB java alloc=63KB native alloc=1605KB free=1722KB
06-13 19:11:34.341 3722 3802 E linker : readlink('/proc/self/fd/28') failed: Permission denied [fd=28]
06-13 19:11:34.341 3722 3802 E linker : warning: unable to get realpath for the library "/data/data/com.google.android.gms/app_fb/f.dex". Will use given name.
06-13 19:11:34.341 3722 3802 W System : ClassLoader referenced unknown path:
06-13 19:11:34.346 3722 3802 D EGL_emulation: eglCreateContext: 0xae5954a0: maj 2 min 0 rcv 2
06-13 19:11:34.346 3722 3802 D EGL_emulation: eglMakeCurrent: 0xae5954a0: ver 2 0 (tinfo 0x9bd75050)
06-13 19:11:34.685 2769 3296 W Conscrypt: Could not set socket write timeout:
06-13 19:11:34.686 2769 3296 W Conscrypt: java.lang.reflect.Method.invoke(Native Method)
06-13 19:11:34.686 2769 3296 W Conscrypt: com.google.android.gms.org.conscrypt.Platform.setSocketWriteTimeout(:com.google.android.gms@11743470:13)
06-13 19:11:34.816 2769 3296 W Conscrypt: Could not set socket write timeout:
06-13 19:11:34.816 2769 3296 W Conscrypt: java.lang.reflect.Method.invoke(Native Method)
06-13 19:11:34.816 2769 3296 W Conscrypt: com.google.android.gms.org.conscrypt.Platform.setSocketWriteTimeout(:com.google.android.gms@11743470:13)
06-13 19:11:35.082 2769 3296 W GLSUser : [AppCertManager] IOException while requesting key:
06-13 19:11:35.082 2769 3296 W GLSUser : java.io.IOException: Invalid device key response.
06-13 19:11:35.082 2769 3296 W GLSUser : at eyw.a(:com.google.android.gms@11743470:14)
06-13 19:11:35.082 2769 3296 W GLSUser : at eyw.a(:com.google.android.gms@11743470:65)
06-13 19:11:35.082 2769 3296 W GLSUser : at eyu.a(:com.google.android.gms@11743470:8)
06-13 19:11:35.082 2769 3296 W GLSUser : at eyq.a(:com.google.android.gms@11743470:1)
06-13 19:11:35.082 2769 3296 W GLSUser : at eyp.a(:com.google.android.gms@11743470:10)
06-13 19:11:35.082 2769 3296 W GLSUser : at com.google.android.gms.auth.account.be.legacy.AuthCronChimeraService.b(:com.google.android.gms@11743470:7)
06-13 19:11:35.082 2769 3296 W GLSUser : at edr.call(:com.google.android.gms@11743470:3)
06-13 19:11:35.082 2769 3296 W GLSUser : at java.util.concurrent.FutureTask.run(FutureTask.java:237)
06-13 19:11:35.082 2769 3296 W GLSUser : at mmu.run(:com.google.android.gms@11743470:26)
06-13 19:11:35.082 2769 3296 W GLSUser : at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
06-13 19:11:35.082 2769 3296 W GLSUser : at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
06-13 19:11:35.082 2769 3296 W GLSUser : at mse.run(:com.google.android.gms@11743470)
06-13 19:11:35.082 2769 3296 W GLSUser : at java.lang.Thread.run(Thread.java:818)
06-13 19:12:00.065 1262 1321 D hwcomposer: hw_composer sent 7 syncs in 60s
06-13 19:13:00.062 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:14:00.058 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:15:00.060 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:16:00.050 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:17:00.045 1262 1321 D hwcomposer: hw_composer sent 8 syncs in 60s
06-13 19:18:00.055 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:19:00.047 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:19:44.119 1948 3853 I AccountManagerService: getTypesVisibleToCaller: isPermitted? true
06-13 19:19:44.560 3722 3733 D EGL_emulation: eglCreateContext: 0xae594a80: maj 2 min 0 rcv 2
06-13 19:19:44.560 3722 3733 D EGL_emulation: eglMakeCurrent: 0xae594a80: ver 2 0 (tinfo 0x9bd75140)
06-13 19:19:44.580 3722 3733 D EGL_emulation: eglCreateContext: 0xae594f00: maj 2 min 0 rcv 2
06-13 19:19:44.581 3722 3733 D EGL_emulation: eglMakeCurrent: 0xae594f00: ver 2 0 (tinfo 0x9bd75140)
06-13 19:19:44.592 3733 3733 W Binder_1: type=1400 audit(0.0:46): avc: denied { read } for name="/" dev="tmpfs" ino=5121 scontext=u:r:untrusted_app:s0:c512,c768 tcontext=u:object_r:device:s0 tclass=dir permissive=0
06-13 19:19:44.622 3733 3733 W Binder_1: type=1400 audit(0.0:47): avc: denied { search } for name="1680" dev="proc" ino=7219 scontext=u:r:untrusted_app:s0:c512,c768 tcontext=u:r:zygote:s0 tclass=dir permissive=0
06-13 19:19:44.762 2769 3296 W Conscrypt: Could not set socket write timeout:
06-13 19:19:44.762 2769 3296 W Conscrypt: java.lang.reflect.Method.invoke(Native Method)
06-13 19:19:44.762 2769 3296 W Conscrypt: com.google.android.gms.org.conscrypt.Platform.setSocketWriteTimeout(:com.google.android.gms@11743470:13)
06-13 19:19:44.874 2769 3296 W Conscrypt: Could not set socket write timeout:
06-13 19:19:44.874 2769 3296 W Conscrypt: java.lang.reflect.Method.invoke(Native Method)
06-13 19:19:44.874 2769 3296 W Conscrypt: com.google.android.gms.org.conscrypt.Platform.setSocketWriteTimeout(:com.google.android.gms@11743470:13)
06-13 19:19:45.135 2769 3296 W GLSUser : [AppCertManager] IOException while requesting key:
06-13 19:19:45.135 2769 3296 W GLSUser : java.io.IOException: Invalid device key response.
06-13 19:19:45.135 2769 3296 W GLSUser : at eyw.a(:com.google.android.gms@11743470:14)
06-13 19:19:45.135 2769 3296 W GLSUser : at eyw.a(:com.google.android.gms@11743470:65)
06-13 19:19:45.135 2769 3296 W GLSUser : at eyu.a(:com.google.android.gms@11743470:8)
06-13 19:19:45.135 2769 3296 W GLSUser : at eyq.a(:com.google.android.gms@11743470:1)
06-13 19:19:45.135 2769 3296 W GLSUser : at eyp.a(:com.google.android.gms@11743470:10)
06-13 19:19:45.135 2769 3296 W GLSUser : at com.google.android.gms.auth.account.be.legacy.AuthCronChimeraService.b(:com.google.android.gms@11743470:7)
06-13 19:19:45.135 2769 3296 W GLSUser : at edr.call(:com.google.android.gms@11743470:3)
06-13 19:19:45.135 2769 3296 W GLSUser : at java.util.concurrent.FutureTask.run(FutureTask.java:237)
06-13 19:19:45.135 2769 3296 W GLSUser : at mmu.run(:com.google.android.gms@11743470:26)
06-13 19:19:45.135 2769 3296 W GLSUser : at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
06-13 19:19:45.135 2769 3296 W GLSUser : at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
06-13 19:19:45.135 2769 3296 W GLSUser : at mse.run(:com.google.android.gms@11743470)
06-13 19:19:45.135 2769 3296 W GLSUser : at java.lang.Thread.run(Thread.java:818)
06-13 19:20:00.055 1262 1321 D hwcomposer: hw_composer sent 8 syncs in 60s
06-13 19:21:00.054 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:22:00.058 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:22:32.982 1948 1961 I UsageStatsService: User[0] Flushing usage stats to disk
06-13 19:23:00.044 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:24:00.050 1262 1321 D hwcomposer: hw_composer sent 5 syncs in 60s
06-13 19:25:00.070 1262 1321 D hwcomposer: hw_composer sent 9 syncs in 60s

NOTE 2: I can't seem to set a Label :)

[King-of-Spades]

@owenniblock Since you referenced the project I maintain as part of the reproduction, I issued a release snapshot of that version so it's a fixed reference point. I don't anticipate any changes in the code that would alter the reproducibility of this bug, but here's that release reference point just in case: https://github.com/King-of-Spades/AppCenter-Test-Samples/releases/tag/0.1-pre2

[jonathanpeppers]

@owenniblock am I right in thinking this is an issue with UITest and not Xamarin.Android itself?

[owenniblock]

@jonathanpeppers - we don't think it's an issue with UITest. Nothing is changing other than the VS 4 Mac versioning - we suspect that it's a bug in HTTP connection between the client and the server running on the Android device.

It's hard to identify exactly where the issue is so I wasn't sure where to log it - so if there's anything we can do to better identify the issue - please let us know.

@King-of-Spades - do you know if we also logged this with VS 4 Mac team yet?

[jonathanpeppers]

So it is only a VS for Mac change, no upgrade to Xamarin.Android occurred?

[owenniblock]

When you upgrade VS 4 Mac it moves the Xamarin.Android dependency from:
8.3.3.2
To:
8.3.99.12

I logged it here because the same change doesn't seem to affect the iOS server - if you can think of a way we can debug better what's happening under the hood then I am happy to dig deeper and try to identify if Xamarin.Android is where the issue lies or if it's somewhere else 🙂

[jonathanpeppers]

So if you run adb logcat | grep calabash while running a single test:

06-15 12:14:10.091 20344 20344 I System.out: Failure file: /data/user/0/com.companyname.UITestDemo.test/files/calabash_failure.out
06-15 12:14:10.091 20344 20344 I System.out: Finished file: /data/user/0/com.companyname.UITestDemo.test/files/calabash_finished.out
06-15 12:14:10.792 20344 20344 I System.out: Failure file: /data/user/0/com.companyname.UITestDemo.test/files/calabash_failure.out
06-15 12:14:10.793 20344 20344 I System.out: Finished file: /data/user/0/com.companyname.UITestDemo.test/files/calabash_finished.out
06-15 12:14:11.567 21036 21036 I calabash: Test server port: 57472
06-15 12:14:11.632 21036 21036 I calabash: Instantiating http server at 57472

But if I try to read these log files from calabash:

$ adb shell
walleye:/ $ cat /data/user/0/com.companyname.UITestDemo.test/files/calabash_failure.out
cat: /data/user/0/com.companyname.UITestDemo.test/files/calabash_failure.out: No such file or directory

I also noticed the app doesn't start, but if I just launch the project in VS for Mac it works fine.

Here is a full adb logcat: logcat.txt

I'm afraid someone from UITest will need to chime in here as to what we should look for.

[King-of-Spades]

@owenniblock To my knowledge this issue is not currently logged with the VS 4 Mac team.

[King-of-Spades]

@owenniblock Should I just file my original data for the issue using the https://docs.microsoft.com/en-us/visualstudio/mac/report-a-problem process?

[owenniblock]

@jonathanpeppers - thanks for helping me with this - I've been digging and I believe that you are correct - this is not a Xamarin.Android issue (the issue lies elsewhere). I'm going to write down my findings here and then hopefully we can work out the best place for this 🙂

The code on our side causing this issue

We have a call to a webservice on the device:

response = _HttpClient.SendAsync(request, cts.Token).Result;

Which receives an expected error and we retry until the service is ready:

bool ShouldRetryOnWebExceptionStatus(Exception ex, IList<WebExceptionStatus> status)
        {
            var webException = ex is WebException ?
                ex as WebException : //Mono
                ex.InnerException as WebException; //.NET

            if (webException == null)
            {
                Log.Info("Exception is not a WebException: " + ex);
                return false;
            }

            Log.Info("Checking for retry against WebException Status: " + webException.Status.ToString());

            if (webException != null && status.Contains(webException.Status))
            {
                return true;
            }

            return false;
        }

This is our list of acceptable exception Statuses:

                    var retryExceptions = new[]
                    {
                        WebExceptionStatus.ReceiveFailure,
                        WebExceptionStatus.ConnectionClosed,
                        WebExceptionStatus.ConnectFailure,
                        WebExceptionStatus.KeepAliveFailure,
                    };

I have added some logging to the above method so we can see what's happening more easily.

Behaviour on current stable branch of VS 4 Mac

When we run this on the current stable branch - the call to System.Net.HttpClient returns an expected error:

{System.Net.Http.HttpRequestException: An error occurred while sending the request ---> System.Net.WebException: Error getting response stream (ReadDone1): ReceiveFailure ---> System.IO.IOException: Unable to read data from the transport connection: Connection reset by peer. ---> System.Net.Sockets.SocketException: Connection reset by peer
  at System.Net.Sockets.Socket.EndReceive (System.IAsyncResult asyncResult) [0x0000c] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System/net/System/Net/Sockets/Socket.cs:4522 
  at System.Net.Sockets.NetworkStream.EndRead (System.IAsyncResult asyncResult) [0x00057] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System/net/System/Net/Sockets/NetworkStream.cs:858 
   --- End of inner exception stack trace ---
  at System.Net.Sockets.NetworkStream.EndRead (System.IAsyncResult asyncResult) [0x0007c] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System/net/System/Net/Sockets/NetworkStream.cs:870 
  at System.Net.WebConnection.ReadDone (System.IAsyncResult result) [0x0001b] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/System/System.Net/WebConnection.cs:467 
   --- End of inner exception stack trace ---
  at System.Net.HttpWebRequest.EndGetResponse (System.IAsyncResult asyncResult) [0x00052] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/System/System.Net/HttpWebRequest.cs:1031 
  at System.Threading.Tasks.TaskFactory`1[TResult].FromAsyncCoreLogic (System.IAsyncResult iar, System.Func`2[T,TResult] endFunction, System.Action`1[T] endAction, System.Threading.Tasks.Task`1[TResult] promise, System.Boolean requiresSynchronization) [0x0000f] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/threading/Tasks/FutureFactory.cs:550 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:152 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535 
  at System.Net.Http.HttpClientHandler+<SendAsync>d__64.MoveNext () [0x003d3] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/System.Net.Http/System.Net.Http/HttpClientHandler.cs:402 
   --- End of inner exception stack trace ---
  at System.Net.Http.HttpClientHandler+<SendAsync>d__64.MoveNext () [0x0046c] in /Users/builder/jenkins/workspace/build-package-osx-mono/2017-12/external/bockbuild/builds/mono-x64/mcs/class/System.Net.Http/System.Net.Http/HttpClientHandler.cs:406 
--- End of stack trace from previous location where exception was thrown ---
  at Xamarin.UITest.Shared.Http.HttpClient.SendData (System.String endpoint, System.String method, System.Net.Http.HttpContent content, Xamarin.UITest.Shared.Http.ExceptionPolicy exceptionPolicy, System.Nullable`1[T] timeOut) [0x000e0] in /Users/owenniblock/Xamarin.UITest/src/Xamarin.UITest.Shared/Http/HttpClient.cs:220 
  at Xamarin.UITest.Shared.Http.HttpClient.Post (System.String endpoint, System.String arguments, Xamarin.UITest.Shared.Http.ExceptionPolicy exceptionPolicy, System.Nullable`1[T] timeOut) [0x0001b] in /Users/owenniblock/Xamarin.UITest/src/Xamarin.UITest.Shared/Http/HttpClient.cs:159 
  at Xamarin.UITest.Shared.Http.HttpClient.PostUntilExpectedResultReceived (System.String endpoint, System.String arguments, System.String expectedContent, System.Int32 retries) [0x0001c] in /Users/owenniblock/Xamarin.UITest/src/Xamarin.UITest.Shared/Http/HttpClient.cs:121 }
	base: {System.Exception}

We retry because we're getting a Status of WebExceptionStatus.ReceiveFailure

Behaviour on current beta branch of VS 4 Mac

When running on the beta branch - we see 2 different behaviours - in the first - the exception looks almost identical but we're getting the Status as: WebExceptionStatus.UnknownError

Other times - the exception we receive does not have an InnerException of Type WebException (so we can't get the Status):

Exception is not a WebException: System.Net.Http.HttpRequestException: An error occurred while sending the request ---> System.IO.IOException: Unable to write data to the transport connection: The socket is not connected. ---> System.Net.Sockets.SocketException: The socket is not connected
  at System.Net.Sockets.Socket.BeginSend (System.Byte[] buffer, System.Int32 offset, System.Int32 size, System.Net.Sockets.SocketFlags socketFlags, System.AsyncCallback callback, System.Object state) [0x00023] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System/net/System/Net/Sockets/Socket.cs:3490 
  at System.Net.Sockets.NetworkStream.BeginWrite (System.Byte[] buffer, System.Int32 offset, System.Int32 size, System.AsyncCallback callback, System.Object state) [0x0009b] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System/net/System/Net/Sockets/NetworkStream.cs:934 
   --- End of inner exception stack trace ---
  at System.Net.Sockets.NetworkStream.BeginWrite (System.Byte[] buffer, System.Int32 offset, System.Int32 size, System.AsyncCallback callback, System.Object state) [0x000c7] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System/net/System/Net/Sockets/NetworkStream.cs:954 
  at System.IO.Stream+<>c.<BeginEndWriteAsync>b__53_0 (System.IO.Stream stream, System.IO.Stream+ReadWriteParameters args, System.AsyncCallback callback, System.Object state) [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/io/stream.cs:729 
  at System.Threading.Tasks.TaskFactory`1[TResult].FromAsyncTrim[TInstance,TArgs] (TInstance thisRef, TArgs args, System.Func`5[T1,T2,T3,T4,TResult] beginMethod, System.Func`3[T1,T2,TResult] endMethod) [0x00008] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/threading/Tasks/FutureFactory.cs:1349 
  at System.IO.Stream.BeginEndWriteAsync (System.Byte[] buffer, System.Int32 offset, System.Int32 count) [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/io/stream.cs:727 
  at System.IO.Stream.WriteAsync (System.Byte[] buffer, System.Int32 offset, System.Int32 count, System.Threading.CancellationToken cancellationToken) [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/io/stream.cs:719 
  at System.Net.WebRequestStream+<ProcessWrite>d__33.MoveNext () [0x001f5] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/System/System.Net/WebRequestStream.cs:246 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable+ConfiguredTaskAwaiter.GetResult () [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:447 
  at System.Net.WebRequestStream+<WriteAsyncInner>d__32.MoveNext () [0x001aa] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/System/System.Net/WebRequestStream.cs:195 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable+ConfiguredTaskAwaiter.GetResult () [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:447 
  at System.Net.Http.HttpClientHandler+<SendAsync>d__64.MoveNext () [0x00324] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/System.Net.Http/System.Net.Http/HttpClientHandler.cs:393 
   --- End of inner exception stack trace ---
  at System.Net.Http.HttpClientHandler+<SendAsync>d__64.MoveNext () [0x0047d] in /Users/builder/jenkins/workspace/build-package-osx-mono/2018-02/external/bockbuild/builds/mono-x64/mcs/class/System.Net.Http/System.Net.Http/HttpClientHandler.cs:408 
--- End of stack trace from previous location where exception was thrown ---
  at Xamarin.UITest.Shared.Http.HttpClient.SendData (System.String endpoint, System.String method, System.Net.Http.HttpContent content, Xamarin.UITest.Shared.Http.ExceptionPolicy exceptionPolicy, System.Nullable`1[T] timeOut) [0x000c7] in <26c8ed4595584c60887b32e26a2f88cc>:0 
  at Xamarin.UITest.Shared.Http.HttpClient.Post (System.String endpoint, System.String arguments, Xamarin.UITest.Shared.Http.ExceptionPolicy exceptionPolicy, System.Nullable`1[T] timeOut) [0x00014] in <26c8ed4595584c60887b32e26a2f88cc>:0 
  at Xamarin.UITest.Shared.Http.HttpClient.PostUntilExpectedResultReceived (System.String endpoint, System.String arguments, System.String expectedContent, System.Int32 retries) [0x0001a] in <26c8ed4595584c60887b32e26a2f88cc>:0

[jonathanpeppers]

Overall I'm guessing changes to mono and the HTTP stack have caused your issue.

It seems like HttpRequestException is a valid exception that should be caught and retried. It also supports HTTP status codes, I thought.

Is this code running on the device? or on the desktop inside an NUnit test? If running on the desktop, it's likely nothing to do with Xamarin.Android at all.

Side note

response = _HttpClient.SendAsync(request, cts.Token).Result;

Oh dear... Can this be refactored to use async/await?

I'm closing this for now, feel free to reopen if you find something that might be an issue in Xamarin.Android.

[felipeslongo]

I had the exact same problem in my Xamarin.Android UI Tests.
To solve it we had to downgrade our mono version.

[imrohitsinghal]

@felipeslongo I am also facing the same issue. How can I downgrade the mono version?