Dotnet 10 Blazor web publish - has something changed with lazy loading?

[Stuart88]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

My Blazor web application has a lot of lazy loading of wasm assemblies, which works fine with dotnet 9

I'm now trying dotnet 10 rc2, and it still works fine when running local debug on my machine.

But when I publish it, the publish output is failing with

..\10.0.0-rc.2.25502.107\build\Microsoft.NET.Sdk.WebAssembly.Browser.targets(804,5): 

Error BLAZORSDK1001: Unable to find

Web.Client.Portal.wasm;
BlazorPro.BlazorSize.wasm;
Cropper.Blazor.wasm;
zxcvbn-core.wasm;
System.Web.HttpUtility.wasm;
System.Runtime.Serialization.Primitives.wasm;
CsvHelper.wasm;
zxing.wasm;
Microsoft.CSharp.wasm;
System.Data.Common.wasm;
System.Diagnostics.TraceSource.wasm;
System.Drawing.wasm;
System.Drawing.Primitives.wasm;
System.Runtime.Serialization.Formatters.wasm'

to be lazy loaded later. 
Confirm that project or package references are included and the reference is used in the project.

Does something need to change with the way the publish instructions are given?

The publish profile looks like this:

<Project>
  <PropertyGroup>
    <DeleteExistingFiles>false</DeleteExistingFiles>
    <ExcludeApp_Data>false</ExcludeApp_Data>
    <LaunchSiteAfterPublish>true</LaunchSiteAfterPublish>
    <LastUsedBuildConfiguration>Debug</LastUsedBuildConfiguration>
    <LastUsedPlatform>Any CPU</LastUsedPlatform>
    <PublishProvider>FileSystem</PublishProvider>
    <WebPublishMethod>FileSystem</WebPublishMethod>
    <_TargetId>Folder</_TargetId>
    <SiteUrlToLaunchAfterPublish />
    <TargetFramework>net10.0</TargetFramework>
    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
    <ProjectGuid>fd2de88c-73e3-4302-8ded-df942e424017</ProjectGuid>
    <SelfContained>false</SelfContained>
  </PropertyGroup>
</Project>

And this is how my Web.Client csproj looks, with the setup for lazy loading (and worked fine when publishing with dotnet 9).

<PropertyGroup>
  <TargetFramework>net10.0</TargetFramework>
  <ImplicitUsings>enable</ImplicitUsings>
  <Nullable>enable</Nullable>
  <NoDefaultLaunchSettingsFile>true</NoDefaultLaunchSettingsFile>
  <StaticWebAssetProjectMode>Default</StaticWebAssetProjectMode>
  <EnableDynamicLoading>true</EnableDynamicLoading>
</PropertyGroup>

<PropertyGroup>
  <PublishTrimmed>true</PublishTrimmed>
  <BlazorWebAssemblyLoadAllGlobalizationData>false</BlazorWebAssemblyLoadAllGlobalizationData>
  <InvariantGlobalization>true</InvariantGlobalization>
  <TrimSymbols>true</TrimSymbols>
</PropertyGroup>

<PropertyGroup Condition="'$(Configuration)' == 'DevDeploy'">
  <PublishTrimmed>false</PublishTrimmed>
  <BlazorWebAssemblyLoadAllGlobalizationData>true</BlazorWebAssemblyLoadAllGlobalizationData>
  <InvariantGlobalization>false</InvariantGlobalization>
  <TrimSymbols>false</TrimSymbols>
</PropertyGroup>


<ItemGroup>
  <PackageReference Include="Blazored.LocalStorage" Version="4.5.0" />
  <PackageReference Include="CodeBeam.MudBlazor.Extensions" Version="8.2.5" />
  <PackageReference Include="Cropper.Blazor" Version="1.4.2" />
  <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="10.0.0-rc.2.25502.107" />
  <PackageReference Include="MudBlazor" Version="8.14.0" />
  <PackageReference Include="zxcvbn-core" Version="7.0.92" />
  <PackageReference Include="BlazorPro.BlazorSize" Version="9.0.0" />
</ItemGroup>

<ItemGroup>
  <BlazorWebAssemblyLazyLoad Include="Web.Client.Portal.wasm"  />
  <BlazorWebAssemblyLazyLoad Include="BlazorPro.BlazorSize.wasm" />
  <BlazorWebAssemblyLazyLoad Include="Cropper.Blazor.wasm" />
  <BlazorWebAssemblyLazyLoad Include="zxcvbn-core.wasm" />
  <BlazorWebAssemblyLazyLoad Include="System.Web.HttpUtility.wasm" />
  <BlazorWebAssemblyLazyLoad Include="System.Runtime.Serialization.Primitives.wasm" />


  <!--
  These are not used anywhere but are internally created during publish
  Tried aggressive trimming but it became messy due to various items being referenced via reflection. 
  Discarding via lazy loading is easier to manage.
  -->
  <BlazorWebAssemblyLazyLoad Include="CsvHelper.wasm" />
  <BlazorWebAssemblyLazyLoad Include="zxing.wasm" />
  <BlazorWebAssemblyLazyLoad Include="Microsoft.CSharp.wasm" />
  <BlazorWebAssemblyLazyLoad Include="System.Data.Common.wasm" />
  <BlazorWebAssemblyLazyLoad Include="System.Diagnostics.TraceSource.wasm" />
  <BlazorWebAssemblyLazyLoad Include="System.Drawing.wasm" />
  <BlazorWebAssemblyLazyLoad Include="System.Drawing.Primitives.wasm" />
  <BlazorWebAssemblyLazyLoad Include="System.Runtime.Serialization.Formatters.wasm" />
</ItemGroup>
  
<ItemGroup>
  <TrimmerRootAssembly Include="Web.Client.Portal" />
  <TrimmerRootAssembly Include="BlazorPro.BlazorSize" />
  <TrimmerRootAssembly Include="Cropper.Blazor" />
  <TrimmerRootAssembly Include="zxcvbn-core" />
</ItemGroup>

<ItemGroup>
  <ProjectReference Include="..\..\Shared\Shared.csproj" />
  <ProjectReference Include="..\..\Web.Client.Portal\Web.Client.Portal.csproj" />
  <ProjectReference Include="..\..\Web.Client.Shared\Web.Client.Common.csproj" />
</ItemGroup>

The same failure occurs whether I publish as debug or release.

Thanks

Expected Behavior

dotnet publish should work

Steps To Reproduce

No response

Exceptions (if any)

..\10.0.0-rc.2.25502.107\build\Microsoft.NET.Sdk.WebAssembly.Browser.targets(804,5): 

Error BLAZORSDK1001: Unable to find

Web.Client.Portal.wasm;
BlazorPro.BlazorSize.wasm;
Cropper.Blazor.wasm;
zxcvbn-core.wasm;
System.Web.HttpUtility.wasm;
System.Runtime.Serialization.Primitives.wasm;
CsvHelper.wasm;
zxing.wasm;
Microsoft.CSharp.wasm;
System.Data.Common.wasm;
System.Diagnostics.TraceSource.wasm;
System.Drawing.wasm;
System.Drawing.Primitives.wasm;
System.Runtime.Serialization.Formatters.wasm'

to be lazy loaded later. 
Confirm that project or package references are included and the reference is used in the project.

.NET Version

10 RC2

[Stuart88]

I have found this issue (#42336)

which looks similar to mine, but the solution there was to just remove the problem assemblies from csproj.

In my case, all the lazy loaded assemblies in csproj are mentioned in the publish error message. I can't remove any from csproj because then my client app errors with "no assemblies marked for lazy loading" when it attempts to load them.

[javiercn]

@maraf can you take a look?

@Stuart88 can you try with the nightly RTM bits?

[Stuart88]

@javiercn

Sorry I'm not sure what 'nightly RTM bits' means!

Anyway I've unfortunately just had to revert my project back to dotnet 9. I found a breaking issue which is likely specific to my solution with no easy to way to fix.

It's not relevant to the above issue but for clarity I'll explain:

On one specific call to NavigationManager.NavigateTo("/") I was hitting an "element not found" javascript error within blazor.web.js with no obvious sign for what's causing it. Presumably it's related to elements being destroyed while the framework expects them to still be there. The issue only occurs with dotnet 10, but for all I know it might be due to some sloppy code in one of my components which only works on dotnet 9 through sheer luck.

I'll revisit dotnet 10 when the full release is out (next week I think?), and will update here / submit new issues if needed.

Thanks for the fast response on this one

[maraf]

Thank you for the report. It is a known issue with publish in RC2. The issue fixed for the final .NET 10 release. There is a workaround for RC2, see #64049 (comment)