[iOS] Attempting to JIT compile method InitializeComponent while running in aot-only mode.

Description

Hi,

I keep getting this exception and crash when I run the app in a physical device in Release mode (I turned on debug in release to catch this exception that only happens in Release).

Attempting to JIT compile method 'void OpenStockApp.Pages.Alerts.NotificationsPageIos:InitializeComponent ()' while running in aot-only mode.

I only get it when I use a CollectionView inside a ContentPage created by Shell.

I am trying to make a smaller reproduction repo from my main project where I found this issue: https://github.com/StockDrops/OpenStockApp/blob/rc3-ios-publish/OpenStockApp/Pages/MobileShell.xaml

I have my mobile shell pointing to a page which is defined here:

https://github.com/StockDrops/OpenStockApp/blob/rc3-ios-publish/OpenStockApp/Pages/Notifications/NotificationsPageIos.xaml

And when I leave the collectionview in it, and I run it on device in release mode I get the above error.

If I comment it out, I can run it fine, until I navigate to another page with a collectionview in it, and it crashes again with the same exception.

This is the stack trace of the error:

The exception:

This is the page that gets loaded by the Shell on startup:

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:vm="clr-namespace:OpenStockApp.ViewModels"
             xmlns:notifications="clr-namespace:OpenStockApp.ViewModels.Notifications"
             xmlns:viewcore="clr-namespace:OpenStockApp.Core.Maui.Views;assembly=OpenStockApp.Core.Maui"
             xmlns:mct="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"
             xmlns:mct2="clr-namespace:CommunityToolkit.Maui;assembly=CommunityToolkit.Maui"
             xmlns:modelsapi="clr-namespace:OpenStockApi.Core.Models.Searches;assembly=OpenStockApi.Core"
             xmlns:views="clr-namespace:OpenStockApp.Views"
             xmlns:main="clr-namespace:OpenStockApp"
             x:DataType="notifications:NotificationsPageViewModel"
             x:Class="OpenStockApp.Pages.Alerts.NotificationsPageIos"
             x:Name="page"
             Title="Notifications Hub"
             >
    <ContentPage.Resources>
        <ResourceDictionary>
            <mct:IsStringNotNullOrEmptyConverter x:Key="IsNotNullOrEmptyConverter"/>
            <mct:BoolToObjectConverter x:Key="BoolToZIndexConverter" TrueObject="1" FalseObject="100" />
            <mct:BoolToObjectConverter x:Key="BoolToObjectConverter" TrueObject="Busy... Please wait..." FalseObject="Refresh List From Server" />
            <mct:InvertedBoolConverter x:Key="InvertedBoolConverter" />
        </ResourceDictionary>
    </ContentPage.Resources>
    <!--<ContentPage.Behaviors>
        <mct:EventToCommandBehavior EventName="NavigatedTo"
                                    Command="{Binding LoadPreviousResults}"/>
    RemainingItemsThreshold="4"
                                RemainingItemsThresholdReachedCommand="{Binding LoadMoreCommand}"
    </ContentPage.Behaviors>-->
    <Grid Margin="0">
        
        <CollectionView ItemsSource="{Binding Results}"
                    ItemsUpdatingScrollMode="{OnPlatform Default='KeepItemsInView', iOS='KeepItemsInView'}"
                    SelectionMode="None"
                    Margin="5,5,5,10"
                    ZIndex="50"
                    x:Name="collectionView">
        <CollectionView.Header>
                <Grid HeightRequest="195"
                  Margin="0,0,10,0">
                    <StackLayout IsVisible="{Binding IsLoggedIn}"
                                 HorizontalOptions="CenterAndExpand">
                    <main:ConnectionIndicatorView IsConnected="{Binding IsConnected}"
                                                      ConnectCommand="{Binding ConnectCommand}"
                                                      HorizontalOptions="Center"/>
                    <Button Grid.Row="0"
                            Grid.Column="1"
                            VerticalOptions="Start"
                            HorizontalOptions="Center"
                            Text="Send Test Notification" 
                            FontAutoScalingEnabled="True"
                            LineBreakMode="WordWrap"
                            Command="{Binding TestNotificationCommand}"
                            IsVisible="{Binding IsLoggedIn}"
                            Margin="0,5,0,5"/>
                    <Frame CornerRadius="5"
                           HeightRequest="110"                     
                           Margin="{OnPlatform Default=4, iOS=15}"                           
                           BackgroundColor="{AppThemeBinding Dark={StaticResource SecondaryColor}, Light={StaticResource BackgroundColor}}"
                           IsVisible="{Binding IsLoggedIn}">
                        <StackLayout Grid.Row="1" Orientation="Horizontal">
                            <StackLayout Orientation="Vertical">
                                <Label Text="Enable alert settings" 
                                           VerticalOptions="Center"
                                           Margin="{OnPlatform Default='10,0,10,0', Android='0,0,0,0', iOS='0,0,0,10'} "/>
                                <Switch IsToggled="{Binding HasToApplyFilterSettings}"
                                                VerticalOptions="Center"
                                                HorizontalOptions="Center">
                                    <Switch.Behaviors>
                                        <mct:EventToCommandBehavior EventName="Toggled"
                                                                    Command="{Binding ApplyFilterSettings}"/>
                                    </Switch.Behaviors>
                                </Switch>
                                <views:SocialButtons VerticalOptions="Center" Margin="10,0,10,0" IsVisible="{OnPlatform Default='False', Android='True'}"  />
                                <views:SocialButtons VerticalOptions="Center" Margin="10,0,10,0" IsVisible="{OnPlatform Default='True', Android='False'}"  />
                            </StackLayout>
                            <StackLayout>
                                <views:SocialButtons VerticalOptions="Center" Margin="5,0,20,0" IsVisible="{OnPlatform Default='False', Android='True', iOS='True'}"  />
                            </StackLayout>
                        </StackLayout>
                    </Frame>
                </StackLayout>

            </Grid>
        </CollectionView.Header>
        <CollectionView.ItemsLayout>
            <GridItemsLayout Orientation="Vertical"
                                     Span="{OnPlatform Android=1, iOS=1, Default=1}"
                                     VerticalItemSpacing="10"
                                     />
        </CollectionView.ItemsLayout>
        <CollectionView.ItemTemplate>
            <DataTemplate x:DataType="modelsapi:Result">

                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="100"/>
                        <RowDefinition Height="160"/>
                        <RowDefinition Height="100"/>
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="3*"/>
                        <ColumnDefinition Width="1*" />
                    </Grid.ColumnDefinitions>
                    <StackLayout Grid.Column="0" Grid.Row="0" Margin="25">
                        <Label Text="{Binding Sku.Model.Name}" 
                                           MaximumWidthRequest="80"
                                   Style="{StaticResource ListTitleStyle}" 
                                       VerticalOptions="Center"
                                   LineBreakMode="WordWrap"
                                   TextTransform="Uppercase"/>
                        <Label Text="{Binding Sku.Retailer.Name}" Margin="0,4,0,4" />
                        <Label Text="{Binding Price}" />
                        <Label Text="{Binding DateTimeFound, StringFormat='{0:g}'}"/>

                    </StackLayout>
                    <StackLayout Grid.Column="1" Grid.Row="0"  Margin="{OnPlatform Default='10', UWP=25}">

                        <Image Source="{Binding ThumbnailUrl}" 
                                           HeightRequest="{OnPlatform Default=80, Android=50, iOS=50}"
                                           Aspect="AspectFit"  IsVisible="{Binding ThumbnailUrl, Converter={StaticResource IsNotNullOrEmptyConverter}}" Margin="0"  />
                        <Label Text="{Binding Id, StringFormat='Id: {0}'}"
                                       VerticalOptions="Start"
                                           Margin="{OnPlatform Default='0,1,0,1', UWP='0,10,0,10', iOS='0,1,0,1'}"/>

                    </StackLayout>
                    <StackLayout Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2" Margin="20">
                        <Image Source="{Binding ImageUrl}"
                               IsVisible="{OnPlatform iOS={Binding ImageLicensed}, Default='True', MacCatalyst={Binding ImageLicensed}}"
                               HeightRequest="120"
                                Aspect="AspectFit" Margin="0,10,0,10">
                            <Image.Clip>
                                    <RoundRectangleGeometry CornerRadius="10" Rect="10,10,120,120" />
                            </Image.Clip>
                        </Image>

                    </StackLayout>
                    <StackLayout Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="2" Margin="20">

                        <views:HyperlinkButton Text="Product Url" Url="{Binding ProductUrl}" Margin="2" />
                        <views:HyperlinkButton Url="{Binding AtcUrl}" Text="Add To Cart Url" IsVisible="{Binding AtcUrl, Converter={StaticResource IsNotNullOrEmptyConverter}}" Margin="2"/>
                    </StackLayout>
                </Grid>

            </DataTemplate>
        </CollectionView.ItemTemplate>
        <CollectionView.Footer>
            <Grid IsVisible="{Binding IsLoggedIn}">
                <Button Margin="0,2,0,2"
                            ZIndex="50"
                            Text="Load More?"
                            MinimumWidthRequest="{OnPlatform Android=100, iOS=100, UWP=300}"
                            HorizontalOptions="Center"
                            FontSize="Medium"
                            FontAttributes="Bold"
                            IsVisible="{Binding EndReached, Converter={StaticResource InvertedBoolConverter}}"
                            Command="{Binding LoadMoreCommand}"/>
                <Button Margin="0,2,0,2"
                            MinimumWidthRequest="{OnPlatform Android=100, iOS=100, UWP=300}"
                            HorizontalOptions="Center"
                            FontSize="Medium"
                            FontAttributes="Bold"
                            IsEnabled="False"
                            Text="End Reached"
                            IsVisible="{Binding EndReached}"/>
            </Grid>
        </CollectionView.Footer>
    </CollectionView>
        <!--<views:LogInView IsLoggedIn="{Binding IsLoggedIn}"
                            LogInCommand="{Binding LogIn}"
                            Grid.Row="0"
                            ZIndex="{Binding IsLoggedIn, Converter={StaticResource BoolToZIndexConverter}}"/>-->
    </Grid>
</ContentPage>

I haven’t been able to know exactly what in the XAML causes the InitializeMethod to try to JIT compile something.

Steps to Reproduce

1. Not sure yet.

Version with bug

Release Candidate 3 (current)

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

ios 15

Did you find any workaround?

None yet

Relevant log output

**System.ExecutionEngineException:** 'Loading...'

Thread finished: <Thread Pool> #8
Thread finished: <Thread Pool> #6
The thread 0x8 has exited with code 0 (0x0).
The thread 0x6 has exited with code 0 (0x0).
Thread started: <Thread Pool> #9

[svaldetero]

I have been getting this error message in numerous spots in my MAUI app in Release on iPhone. Mine all seem to be related to using LINQ. The most infuriating thing is it doesn’t happen when debugging on a device which should be AOT’d also. I only discover it when pushing out a build to users and it crashes.

1. Is there a way to debug and and trigger this issue to I can catch it sooner?
2. Why is LINQ having so much trouble in AOT?

[yunusefendi52]

@StephaneDelcroix setting MauiXamlCValidateOnly not working for me, log:

Set Property: _MauiXamlCValidateOnly=False
Set Property: _MauiXamlCValidateOnly=True

other logs

ValidateOnly=True. Skipping writing assembly.

But looking at the source, it’s working when settings it to -p:MauiXamlCValidateOnly=False -p:_MauiForceXamlCForDebug=True

Set Property: _MauiXamlCValidateOnly=False