I want to “merge” (or “pack”) some .NET assemblies into one.
To achieve this I am trying “ILRepack”.

I am referencing the nuget package ‘ILRepack.MSBuild.Task’ (version 2.0.13) in a class library called “MyCombinedClassLibrary”. When I build this project “MyCombinedClassLibrary” the assemblies “MyClassLibrary1”, “MyClassLibrary2” and “MyClassLibrary3” will be successfully “merged” into one “MyCombinedClassLibrary.dll”. Works as expected.

Now when I am referencing this combined assembly in another project, like a MSTest project, I can not access the classes of the merged assemblies like “MyClassLibrary1.MyClass”.

I have already checked “MyCombinedClassLibrary.dll” with dotPeek. The tool shows that the expected classes are part of the combined dll – and they are public, too. So I don’t get it what I am doing wrong here.

MyCombinedClassLibrary.csproj:

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

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <!-- PACKAGE REFERENCES -->
  <ItemGroup>
    <PackageReference Include="ILRepack.MSBuild.Task" Version="2.0.13" />
  </ItemGroup>

  <!-- ILREPACK CONFIGURATION -->
  <Target Name="ILRepack" AfterTargets="Build" Condition="'$(Configuration)' == 'Release'">
    <PropertyGroup>
      <WorkingDirectory>$(MSBuildThisFileDirectory)bin$(Configuration)</WorkingDirectory>
    </PropertyGroup>
    <ItemGroup>
      <InputAssemblies Include="MyClassLibrary1.dll" />
      <InputAssemblies Include="MyClassLibrary2.dll" />
      <InputAssemblies Include="MyClassLibrary3.dll" />
    </ItemGroup>
    <ItemGroup>
        <InternalizeExcludeAssemblies Include="MyClassLibrary1" />
        <InternalizeExcludeAssemblies Include="MyClassLibrary2" />
        <InternalizeExcludeAssemblies Include="MyClassLibrary3" />
    </ItemGroup>
    <Message Text="MERGING: @(InputAssemblies->'%(Filename)') into $(AssemblyName)" Importance="High" />
    <ILRepack OutputType="$(OutputType)" MainAssembly="$(AssemblyName).dll" OutputAssembly="$(AssemblyName).dll" InputAssemblies="@(InputAssemblies)" InternalizeExcludeAssemblies="@(InternalizeExcludeAssemblies)" WorkingDirectory="$(WorkingDirectory)" />
  </Target>

</Project>

Screenshot of my projects:
projects