Mapperly support for .net framework 4.7.2

[arquill3]

Hello, I have been trying to integrate Mapperly to a .Net Framework 4.7.2 project and I am running into issues. I have modified the project to force it to use C# 9.0 and added roslyn 4.4 nuget package to the project but i have no luck. I keep getting the error - CS0757 A partial method may not have multiple implementing declarations. Was anyone successful with integrating Mapperly with a .Net framework 4.7.2?
I have replicated the exact same code in a .Net 6.0 application, and I have no issues. It works fine.

[latonz]

Does the same code work with .NET Framework 4.8? Could you create a minimal repro on GH (if possible with a failing GH action build)?

[arquill3]

No. I updated the framework to 4.8 and it does not work either. Sorry, I have never done a GH action build but I have invited you to a repo that has the sample project that I am facing an issue with.

[CommonGuy]

I had trouble getting it to work with the "old-style" csproj format, so I converted it to the newer SDK project format: TestWebApplication1-master.zip. This way, Mapperly works without issues. Changing the target framework to .NET 4.7.2 should also work.

It seems like hooking up Mapperly in "old-style" csproj formats is much more difficult (is it even supported?). Sadly, I couldn't find more information on how to accomplish this. But since the newer SDK format is easier and much more compact, I would suggest everyone to just switch to the new format.

---

To clarify, with "old-style" csproj formats, I mean this:

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props"
            Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')"/>

    <PropertyGroup>
        <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
        <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
        <ProjectGuid>{49C6A4B3-8FB9-468B-BEC9-00047A05F0E9}</ProjectGuid>
        <OutputType>Library</OutputType>
        <AppDesignerFolder>Properties</AppDesignerFolder>
        <RootNamespace>ClassLibrary1</RootNamespace>
        <AssemblyName>ClassLibrary1</AssemblyName>
        <TargetFrameworkVersion>v4.8</TargetFrameworkVersion>
        <FileAlignment>512</FileAlignment>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
        <PlatformTarget>AnyCPU</PlatformTarget>
        <DebugSymbols>true</DebugSymbols>
        <DebugType>full</DebugType>
        <Optimize>false</Optimize>
        <OutputPath>bin\Debug\</OutputPath>
        <DefineConstants>DEBUG;TRACE</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
        <PlatformTarget>AnyCPU</PlatformTarget>
        <DebugType>pdbonly</DebugType>
        <Optimize>true</Optimize>
        <OutputPath>bin\Release\</OutputPath>
        <DefineConstants>TRACE</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
    </PropertyGroup>

   <!-- Many more lines omitted -->

    <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets"/>
</Project>

And the more compact SDK style format:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net48</TargetFramework>
    <LangVersion>9</LangVersion>
  </PropertyGroup>
  
  <ItemGroup>
    <PackageReference Include="Riok.Mapperly" Version="3.6.0" PrivateAssets="all" />
  </ItemGroup>
</Project>