.NET NU5104 NoWarn Build Errors

Class1.cs

using System;

namespace bugz
{
    public class Class1
    {
      // This package used to be packable with the .NET Core 3.1.301 SDK but
      // packaging fails with the .NET Core 3.1.401 SDK. The exit code from
      // `dotnet pack` is now 1 indicating failure. This has prevented
      // release builds of some of our libraries.
    }
}

nu5104bug.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <Version>1.2.3</Version>
    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Lucene.Net" Version="4.8.0-beta00011" NoWarn="NU5104" />
  </ItemGroup>

</Project>

test_script.sh

#! /usr/bin/env bash

set -euo pipefail

function run_with_sdk()
{
    sdk_tag=$1
    echo ""
    echo "with SDK $sdk_tag"
    rm -rf bin/ obj/
    docker run -v `pwd`:/test mcr.microsoft.com/dotnet/core/sdk:$sdk_tag bash -c 'if dotnet pack /test; then echo ++ passed. Exit code: $? ++; else echo -- failed. Exit code: $? --; fi'
}

run_with_sdk 3.1.201
run_with_sdk 3.1.301
run_with_sdk 3.1.302
run_with_sdk 3.1.401