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Stuck at building to iOS

Title says it all. I made an iOS app that I can't test. Yes I've connected my Mac agent, everything has latest update. When I hit "Build" it just says in console:

1>------ Build started: Project: Mrs.iOS, Configuration: Debug iPhoneSimulator ------

And its just stuck there.

I have Visual Studio Community Edition, Xcode runs on macOS El Capitan and I want to build it on a simulator.


  • I am having a similar experience though it does eventually build after an unspecified amount of time

  • StreammzStreammz NLMember
    edited January 2017

    The compilation usually takes a long time. Depending on the configuration, it can take minutes for it to complete.
    If you're unsure whether the mac is still compiling, you can open "Activity Monitor" on the mac. Whilst compiling, the cpu usage is usually around 100% by processes such as "mono-sgen64".

    Since you are building for the simulator, I recommend applying these tips to your configuration. It speeds up the build time significantly. Our project currently only takes roughly 15 seconds to build for the simulator, where it took up to a minute before.

  • ChrisColeTechChrisColeTech USMember ✭✭✭

    if youre on the latest version, yeah - the builds are broken.

    Each update makes things worse and worse -- downgrade to get faster speeds.

  • PhilippSumiPhilippSumi USMember ✭✭✭

    Same here - started working on an iOS from Android, and build times are in the realm of minutes. A lot of the XAML that was just fine in Android is breaking on iOS now, so "build, test, repeat" is a nightmare. Please hear us, Xamarin.

  • AnubhavRanjanAnubhavRanjan INXamarin Team Xamurai

    @PhilippSumi Can you please let us know what exactly is breaking up?

    Also, can you share the version information?
    Visual Studio > Help > About > Copy Info

  • PhilippSumiPhilippSumi USMember ✭✭✭
    edited January 2017


    It's a very rocky ride. My issues since I started porting yesterday:

    • generic:List not found in xmlns clr-namespace:System.Collections.Generic. File a bug here:, applied workaround (create non-generic custom collection).
    • ListView isn't working properly - my list with 15 (!) items scrolls super laggy, and screws up the layout in the items on scrolling down. Virtualization is enabled but doesn't help.
    • I have a set of custom controls that on click open editors (such as time picker, date picker or selection lists). Sometimes they work, sometimes they don't (and just nothing happens). Completely random as far as I can tell without any exceptions happening. Not investigated yet.
    • Random NullReferenceException in VisualElement Finalize. I think this should be fixed (there's a PR for XF)
    • Another ListView that has only one item renders two empty cells with separators. Not investigated yet.
    • Something weird, probably while adding a chat message item to a collection bound to by a ListView). Not investigated yet:
      0x00000001000a5b44 0x000000010008dce4 0x0000000101022974 0x0000000100f860cc 0x0000000100f8608c 0x00000001001e7d90 0x0000000100483e44 0x00000001000f8f80 0x000000010015de64 0x0000000100160a4c 0x00000001000e2b4c 0x00000001001e6c34 0x0000000101d64178. Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Application windows are expected to have a root view controller at the end of application launch'

    • TextBox docked to bottom of view is covered by keyboard (I think that's platform specific, not investigated yet)

    • Default property value on a control doesn't seem to be applied, or Color.Accent below cannot be resolved:
      public static readonly BindableProperty CircleColorProperty = BindableProperty.Create(propertyName: "CircleColor", returnType: typeof(Color), declaringType: typeof(CircleIconButton), defaultValue: Color.Accent);

    Here's my VS info:

    Microsoft Visual Studio Enterprise 2017 RC
    Version 15.0.26014.0 D15REL
    Microsoft .NET Framework
    Version 4.6.01586

    Installed Version: Enterprise

    Architecture Diagrams and Analysis Tools 00369-50000-00000-AA373
    Microsoft Architecture Diagrams and Analysis Tools

    Visual Basic 2017 RC 00369-50000-00000-AA373
    Microsoft Visual Basic 2017 RC

    Visual C# 2017 RC 00369-50000-00000-AA373
    Microsoft Visual C# 2017 RC

    Visual F# 4.1 00369-50000-00000-AA373
    Microsoft Visual F# 4.1

    ASP.NET and Web Tools 2016 15.0.21206.0
    ASP.NET and Web Tools 2016

    ASP.NET Web Frameworks and Tools 2013 5.2.41123.0
    For additional information, visit

    Azure App Service Tools v2.9.6 15.0.21130.0
    Azure App Service Tools v2.9.6

    Azure Data Lake Node 1.0
    This package contains the Data Lake integration nodes for Server Explorer.

    Azure Data Lake Tools for Visual Studio 2.2.3100.0
    Microsoft Azure Data Lake Tools for Visual Studio

    Command Bus, Event Stream and Async Manager Merq
    Provides ICommandBus, IEventStream and IAsyncManager MEF services for loosely coupled Visual Studio extension components communication and integration.

    Common Azure Tools 1.8
    Provides common services for use by Azure Mobile Services and Microsoft Azure Tools.

    JavaScript Language Service 2.0
    JavaScript Language Service

    JavaScript Project System 2.0
    JavaScript Project System

    JetBrains ReSharper Ultimate 2016.3 Build 107.0.20161214.141528
    JetBrains ReSharper Ultimate package for Microsoft Visual Studio. For more information about ReSharper Ultimate, visit Copyright © 2017 JetBrains, Inc.

    KofePackagePackage Extension 1.0
    KofePackagePackage Visual Studio Extension Detailed Info

    Microsoft Azure Hive Query Language Service 2.2.3100.0
    Language service for Hive query

    Microsoft Azure Tools 2.9
    Microsoft Azure Tools for Microsoft Visual Studio vNext - v2.9.41121.2

    Microsoft Continuous Delivery Tools for Visual Studio 0.1
    Simplifying the configuration of continuous build integration and continuous build delivery from within the Visual Studio IDE.

    Microsoft MI-Based Debugger 1.0
    Provides support for connecting Visual Studio to MI compatible debuggers

    Mono Debugging for Visual Studio Mono.Debugging.VisualStudio
    Support for debugging Mono processes with Visual Studio.

    Node.js Tools 1.3.41102.00
    Adds support for developing and debugging Node.js apps in Visual Studio

    Node.js Tools - Profiling 1.3.41102.00
    Profiling support for Node.js projects.

    NuGet Package Manager 4.0.0
    NuGet Package Manager in Visual Studio. For more information about NuGet, visit

    Manage localization of all ResX-Based resources in one place. Shows all resources of a solution and let's you edit the strings and their localizations in a well-arranged data grid.

    SQL Server Data Tools 15.1.61124.0
    Microsoft SQL Server Data Tools

    ToolWindowHostedEditor 1.0
    Hosting json editor into a tool window

    TSCPackage Extension 1.0
    TSCPackage Visual Studio Extension Detailed Info

    TypeScript tools for Visual Studio

    Xamarin (7c3dcf2)
    Visual Studio extension to enable development for Xamarin.iOS and Xamarin.Android.

    Xamarin.Android (72366f7)
    Visual Studio extension to enable development for Xamarin.Android.

    Xamarin.iOS (d93ae7e)
    Visual Studio extension to enable development for Xamarin.iOS.

  • AnubhavRanjanAnubhavRanjan INXamarin Team Xamurai
    edited January 2017

    @PhilippSumi Would it be possible for you to contain the issues in a reproducible sample and share it with us?

    Also, it would be great to attach a working sample for the bug
    It would help our engineers to dive deep.

  • PhilippSumiPhilippSumi USMember ✭✭✭

    @AnubhavRanjan I'm afraid it's not an option right now - it breaking in various areas, and taking out the code would be a major issue. I'm supposed to showcase Xamarin at Microsoft's TechDays conference here in Switzerland next week. Right now, I'm just desperatly trying to work around those issues in any way I can :)

    Since the project is sponsered by Microsoft anyway: I could Xamarin access to the source code. Would that be helpful?
    (you could ping me through philipp at (my domain)

  • AlanClarkAlanClark USMember ✭✭✭

    Hi guys. It would be really useful if we could gather more information on this.

    Firstly, we have the Beta channel that you might want to try to see if the issue has already been addressed in our upcoming release. You can always drop back to the Stable channel afterwards if you prefer.

    If that doesn't improve your build times or you're not willing to give it a try for whatever reason then

    Hi guys! We actually have a useful guide for timing apps with some handy hints for speeding up build times:

    I'd suggest taking a look at that.

    If you think you've noticed a slow-down since a recent Xamarin update where your project hasn't changed a whole deal, then it might be worthwhile updating to the Beta channel to see if the issue has already been addressed. Other

    If you drop back and you're seeing quicker build times than the later release then our engineers are probably going to be eager to take a look. In this case I'd suggest filing a bug:

    It'd be great to get people's feedback there!


  • NickKovalskyNickKovalsky USMember ✭✭✭

    AN obvious move would be to implement some sort of progress bar for compile and deploy on mac, when you are developping from windows pc. Atm i can see deploy progress only when on Mac, from pc it's totally dark. And compiling from pc you never know if it's actually compiling or it's (as usual) have broken connection and became stuck.

    Another funny bug here, due to missing windows display of deploy progress, is that when running a signed Release from windows to Mac Xamarin says it was deployed please click on icon. But it wasn't deployed and one cannot easily see that.

  • ajdrakeajdrake Member

    Mine is stuck at building for iOS Windows with a Mac paired as well. It have been running for 30+ minutes with no real status change.

  • AdrianGrigoreAdrianGrigore DEMember ✭✭

    Same here. No status change after over 30 minutes. What makes this even worse: Debugging in the Emulator does not work either since the emulator never stops loading. Visual Studio for Windows is basically useless for iOS development now.

  • MichaelLantMichaelLant CAMember ✭✭

    I'm stuck as well.

    Using VS for Windows, Android works fine. iOS, however, does not.

    It just sits there. VS CPU <1%, so it is just idling. I have even let it run for over an hour to see if it just needed more time - Nope. No emulator is started and canceling a build does not work so I have to kill VS in Task Manager. I have all of the latest updates for Win10 and MacOS High Sierra. As well, VS W10 and VS Mac both have all of the latest updates.

    I don't have Apple hardware, so I can't test to see if it is just a simulator issue or it is more general to the entire build/deploy process.


  • MichaelLantMichaelLant CAMember ✭✭

    Further comments: Using VS Mac, I can successfully build and run the project from my Mac using the emulator on the Mac.

    Also not noted in the previous message is that my W10 had established a connection to my Mac without issues. The issue appears to be with the W10 machine not being able to launch the emulator.


  • JohnHJohnH GBMember ✭✭✭✭✭

    @MichaelLant said:
    Further comments: Using VS Mac, I can successfully build and run the project from my Mac using the emulator on the Mac.

    Also not noted in the previous message is that my W10 had established a connection to my Mac without issues. The issue appears to be with the W10 machine not being able to launch the emulator.


    You mentioned you don't have Mac hardware? How are you building then?
    You must have Mac hardware to be able to build, so if you do, build the solution on the Mac to run the simulator there to make sure it works.

  • MichaelLantMichaelLant CAMember ✭✭


    Mea culpa. I meant to say that I do not have iOS hardware.

    The problem is that the simulator will not run. VS on Win10 simply idles with CPU <1%. I can't even cancel the build. I have to go into Task Manager and kill the VS instance.

    Sorry for the confusion.


  • nefgrixisnefgrixis Member ✭✭
    edited October 2018

    on the Mac I usually kill the mono64 process and run again and it runs fine. Something Microsoft has reported to fix in 15.8.3 of VS, it's been working so far since then.

  • PierceBogganPierceBoggan USForum Administrator, Xamarin Team, Developer Group Leader Xamurai

    Hi all,

    When you hit issues like this, could you please file them via Help > Send Feedback > Report a Problem? This will automatically include diagnostic information. After you do that, feel free to share the link so I can make sure the team is aware of the issue.


  • amirvenusamirvenus USMember ✭✭✭

    My issue is very annoying and it occurs when I clone a project built on a Windows machine and run on VS for Mac.

    Left my Macbook Pro on in the morning and hit Build (Release) and guess what, it's 8 in the evening and it's still building!

    Pressing the stop doesn't do anything as well although the VS is still responsive but I have to force quit it and maybe leave it to build for another day.

  • Seems my case.

    I'm using Jenkins and Windows agent paired with Macmini.
    Sometimes build just hangs after some execution. Ran build with -v:diag parameter, where I see
    Sending Request Xamarin.Messaging.Build.Contracts.ExecuteTaskMessage message, however previous such messages received responce Received Response of Xamarin.Messaging.Build.Contracts.ExecuteTaskMessage to topic build13584tempu/response/xvs/Build/
    VS version 16.3.5
    XCode version (11.1)
    Mac OS - 10.14.6 (Mojave)

  • I was facing the same issue in release mode. But i have change few setting & after that it is working fine.

    1. disable debugging: Options->Build->iOS Debug->uncheck the enable dubugging.
    2. Change Supported Architecture: Options->Build->iOS Build->
      SDK version: default,
      Linker Behaviour: Link Framework SDK only,
      Supported Architecture: ARM64,
    3. You can see other settings in attached screenshot

    Hope, this will help someone.

  • RitaVRitaV Member ✭✭

    @rakeshkumar217, This worked for me. Thanks for the tips.
    However i'm unable to debug my app now. Any idea how i can make both work?

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