Merge pull request #1086 from reactiveui/packages-config-error

Add error case for packages.config to prevent runtime issues

README.md

@@ -86,6 +86,9 @@ Refit currently supports the following platforms and any .NET Standard 2.0 targe
 
 Refit 6 requires at Visual Studio 16.8 or higher, or the .NET SDK 5.0.100 or higher. It can target any .NET Standard 2.0 platform.
 
+Refit 6 does not support the old `packages.config` format for NuGet references (as they do not support analyzers/source generators). You must
+[migrate to PackageReference](https://devblogs.microsoft.com/nuget/migrate-packages-config-to-package-reference/) to use Refit v6 and later.
+
 #### Breaking changes in 6.x
 
 Refit 6 makes [System.Text.Json](https://docs.microsoft.com/en-us/dotnet/standard/serialization/system-text-json-overview) the default JSON serializer. If you'd like to continue to use `Newtonsoft.Json`, add the `Refit.Newtonsoft.Json` NuGet package and set your `ContentSerializer` to `NewtonsoftJsonContentSerializer` on your `RefitSettings` instance. `System.Text.Json` is faster and uses less memory, though not all features are supported. The [migration guide](https://docs.microsoft.com/en-us/dotnet/standard/serialization/system-text-json-migrate-from-newtonsoft-how-to?pivots=dotnet-5-0) contains more details.

Refit/targets/refit.targets

@@ -15,8 +15,13 @@
 
   <Target Name="_RefitMSBuildVersionCheck"
           Condition=" '$([System.Version]::Parse($(_RefitMSBuildMinVersion)).CompareTo($([System.Version]::Parse($(MSBuildVersion)))))' &gt; '0' "
-     BeforeTargets="ResolveAssemblyReferences;Build;Rebuild">
+     BeforeTargets="ResolveAssemblyReferences;Build;Rebuild" >
     <Error
         Text = "Projects using Refit cannot build using MSBuild '$(MSBuildVersion)'. MSBuild '$(_RefitMSBuildMinVersion)' or later is required." />
   </Target>
+
+  <Target Name="_RefitProjectRestoreTypeCheck" BeforeTargets="ResolveAssemblyReferences;Build;Rebuild" DependsOnTargets="_GetRestoreProjectStyle">
+    <Error Condition="'$(RestoreProjectStyle)' == 'PackagesConfig'"
+           Text="Packages.config does not support Analyzers, including Source Generators. Migrate to PackageReference: 'https://devblogs.microsoft.com/nuget/migrate-packages-config-to-package-reference/'" />
+  </Target>
 </Project>