Publishing a blazor wasm, that is served from a backend (through project include), does not populate the importmap

[sleepwalkerffs]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

There is a minimal repo here: minimal-repo.zip
If you navigate into the repo to minimal-repo\WebApplication2 and execute dotnet publish .\WebApplication2.csproj -c Release you will find the index.html in minimal-repo\WebApplication2\bin\Release\net10.0\publish\wwwroot which contains an empty importmap:
<script type="importmap"></script>
This results in a non working blazor app.

Expected Behavior

The importmap should be populated like this:

<script type="importmap">{
  "imports": {
    "./_framework/blazor.webassembly.js": "./_framework/blazor.webassembly.66stpp682q.js",
    "./_framework/dotnet.js": "./_framework/dotnet.8lbghqbqg3.js",
    "./_framework/dotnet.native.js": "./_framework/dotnet.native.xanz2e7ksm.js",
    "./_framework/dotnet.runtime.js": "./_framework/dotnet.runtime.o0qy896u8v.js"
  },
  "scopes": {},
  "integrity": {
    "./_framework/blazor.webassembly.66stpp682q.js": "sha256-3lCWrko3zwspV40aQhs2S/IMkRSarnHRKIdkHhuXIBA=",
    "./_framework/blazor.webassembly.js": "sha256-3lCWrko3zwspV40aQhs2S/IMkRSarnHRKIdkHhuXIBA=",
    "./_framework/dotnet.8lbghqbqg3.js": "sha256-VNjXDaSOqCze1lQpbXefxCqOiepPF9oGAydILjYgIuM=",
    "./_framework/dotnet.js": "sha256-VNjXDaSOqCze1lQpbXefxCqOiepPF9oGAydILjYgIuM=",
    "./_framework/dotnet.native.js": "sha256-uQpMf2vCY3ZTY+nV2gmp8VdAe67PW6h1gInkE7r/PLY=",
    "./_framework/dotnet.native.xanz2e7ksm.js": "sha256-uQpMf2vCY3ZTY+nV2gmp8VdAe67PW6h1gInkE7r/PLY=",
    "./_framework/dotnet.runtime.js": "sha256-yJvgPPUUvavYVmu9VD/fYtMcoEnLVaB0Cr7JAE29btw=",
    "./_framework/dotnet.runtime.o0qy896u8v.js": "sha256-yJvgPPUUvavYVmu9VD/fYtMcoEnLVaB0Cr7JAE29btw="
  }
}</script>

Actual Behavior

The importmap script tag is empty:

<script type="importmap"></script>

Additional Information

When you publish the Blazor wasm directly by navigatng into minimal-repo/Blazor10 and executing dotnet publish .\Blazor10.csproj -c Release the importmap will get populated as shown above in the Expected Result

.NET Version

10.0.100

[ilonatommy]

Thank you, @sleepwalkerffs for the report.
It looks like a duplicate of dotnet/runtime#121993 that is in the process of getting solved.