System.Net.Http version conflict causing build warning

Question

The nuget package Microsoft.Net.Http.2.0.20710.0 is causing me a build warning because of its use of System.Net.Http, Version=2.0.0.0 which is fighting with version 4 coming from another package.

What is the best way around this? Is the package Microsoft.Net.Http.2.0.20710.0 outdated, should I just reference System.Net.Http, Version=4.0.0.0 manually in my project?

The build output is:

  There was a conflict between "System.Net.Http, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" and "System.Net.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
      "System.Net.Http, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" was chosen because it was primary and "System.Net.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" was not.
      References which depend on "System.Net.Http, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" [C:\Working\MyProject\packages\Microsoft.Net.Http.2.0.20710.0\lib\net40\System.Net.Http.dll].
          C:\Working\MyProject\packages\Microsoft.Net.Http.2.0.20710.0\lib\net40\System.Net.Http.dll
            Project file item includes which caused reference "C:\Working\MyProject\packages\Microsoft.Net.Http.2.0.20710.0\lib\net40\System.Net.Http.dll".
              System.Net.Http, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL
      References which depend on "System.Net.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" [C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Net.Http.dll].
          C:\Working\MyProject\packages\Microsoft.AspNet.WebApi.Core.4.0.20710.0\lib\net40\System.Web.Http.dll
            Project file item includes which caused reference "C:\Working\MyProject\packages\Microsoft.AspNet.WebApi.Core.4.0.20710.0\lib\net40\System.Web.Http.dll".
              System.Web.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL
              System.Web.Http.WebHost, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL
          C:\Working\MyProject\packages\Microsoft.AspNet.WebApi.Client.4.0.20710.0\lib\net40\System.Net.Http.Formatting.dll
            Project file item includes which caused reference "C:\Working\MyProject\packages\Microsoft.AspNet.WebApi.Client.4.0.20710.0\lib\net40\System.Net.Http.Formatting.dll".
              System.Web.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL
              System.Net.Http.Formatting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL
              System.Web.Http.WebHost, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL
          C:\Working\MyProject\packages\Microsoft.AspNet.WebApi.WebHost.4.0.20710.0\lib\net40\System.Web.Http.WebHost.dll
            Project file item includes which caused reference "C:\Working\MyProject\packages\Microsoft.AspNet.WebApi.WebHost.4.0.20710.0\lib\net40\System.Web.Http.WebHost.dll".
              System.Web.Http.WebHost, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1578,5): warning MSB3247: Found conflicts between different versions of the same dependent assembly.

Answer 1

You can try the workaround mentioned in this Microsoft Connect bugreport.

Or you can try and add something like this to your Web.config:

  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Net.Http" publicKeyToken="b03f5f7f11d50a3a" />
        <bindingRedirect oldVersion="0.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

Edit:

This is the workaround in the Connect Bug:

modify.......: <Reference Include="System.Net.Http">
to read ......: <Reference Include="System.Net.Http, Version=4.0.0.0">