Set IsPackable=true on Microsoft.AspNetCore.Components.Gateway so Pack produces the shipping nupkg

[danroth27]

Summary

Microsoft.AspNetCore.Components.Gateway is configured as a shipping package (<IsShippingPackage>true</IsShippingPackage>) with a custom <NuspecFile>, but no nupkg has been produced on the dnceng feeds since the project was added in #65982. Root cause: Microsoft.NET.Sdk.Web.ProjectSystem.props defaults IsPackable to false:

<IsPackable Condition="'$(IsPackable)' == ''">false</IsPackable>

Because Gateway uses Sdk="Microsoft.NET.Sdk.Web" and never overrides IsPackable, the Pack target silently no-ops ΓÇö the <NuspecFile> and <IsShippingPackage> settings are ignored. (The Microsoft.AspNetCore.Components.WebAssembly.DevServer project, which is the closest analog and ships correctly, uses plain Microsoft.NET.Sdk and so doesn't hit this default.)

Fix

Set <IsPackable>true</IsPackable> explicitly in Microsoft.AspNetCore.Components.Gateway.csproj. One-line change.

Verification

Before:

> .\eng\build.ps1 -pack -projects src\Components\Gateway\src\Microsoft.AspNetCore.Components.Gateway.csproj
Build succeeded.
    0 Warning(s)
    0 Error(s)
> Get-ChildItem artifacts\packages -Recurse -Filter '*.nupkg'
# (no output ΓÇö no package produced)

After:

> .\eng\build.ps1 -pack -projects src\Components\Gateway\src\Microsoft.AspNetCore.Components.Gateway.csproj
  Successfully created package 'artifacts\packages\Debug\Shipping\Microsoft.AspNetCore.Components.Gateway.11.0.0-dev.nupkg'.
  Successfully created package 'artifacts\packages\Debug\Shipping\Microsoft.AspNetCore.Components.Gateway.11.0.0-dev.symbols.nupkg'.
Build succeeded.

Inspecting the produced nupkg confirms the expected payload:

Path	Notes
Microsoft.AspNetCore.Components.Gateway.nuspec	from existing <NuspecFile>
build/Microsoft.AspNetCore.Components.Gateway.targets	consumer-side props/targets
tools/blazor-gateway.{dll,exe}	the host
tools/Yarp.ReverseProxy.dll, tools/Microsoft.Extensions.ServiceDiscovery*.dll, tools/System.IO.Hashing.dll	dependencies
tools/blazor-gateway.runtimeconfig.json, tools/web.config, tools/blazor-gateway.deps.json	runtime config
THIRD-PARTY-NOTICES.txt, Icon.png	metadata

Why this matters for 11.0 P4

Without this fix, dotnet add package Microsoft.AspNetCore.Components.Gateway --prerelease returns no result on any feed, so the Gateway can only be exercised by building it locally and copying the host bits into a sample.

cc @javiercn

[Copilot]

Pull request overview

This PR fixes packaging for Microsoft.AspNetCore.Components.Gateway so the repo’s pack step actually emits the intended shipping NuGet package. It aligns the Gateway project with the existing custom-nuspec packaging setup already used for similar Components tooling.

Changes:

• Explicitly sets IsPackable=true on Microsoft.AspNetCore.Components.Gateway.
• Documents why the override is required when using Microsoft.NET.Sdk.Web.
• Ensures the existing custom .nuspec-based pack flow can produce the shipping .nupkg.